1.  virtue(n = noun.attribute) moral excellence, virtuousness - the quality of doing what is right and avoiding what is wrong;
is a kind of good, goodness
Derived form adjective virtuous₁

2.  virtue(n = noun.attribute) merit - any admirable quality or attribute; "work of great merit"
is a kind of worth

3.  virtue(n = noun.attribute) chastity, sexual morality - morality with respect to sexual relations;
is a kind of morality
has particulars: honor, honour, pureness, purity
Derived form adjective virtuous₂

4.  virtue(n = noun.attribute) - a particular moral excellence;
is a kind of good, goodness
has particulars: cardinal virtue
Derived form adjective virtuous₁

1.  Manly strength or courage; bravery; daring; spirit; valor. Shak. [1913 Webster]
"Built too strong
For force or virtue ever to expugn." [1913 Webster]

2.  Active quality or power; capacity or power adequate to the production of a given effect; energy; strength; potency; efficacy; as, the virtue of a medicine. [1913 Webster]
"Jesus, immediately knowing in himself that virtue had gone out of him, turned him about." [1913 Webster]
"A man was driven to depend for his security against misunderstanding, upon the pure virtue of his syntax." [1913 Webster]
"The virtue of his midnight agony." [1913 Webster]

3.  Energy or influence operating without contact of the material or sensible substance. [1913 Webster]
"She moves the body which she doth possess,
Yet no part toucheth, but by virtue's touch." [1913 Webster]

4.  Excellence; value; merit; meritoriousness; worth. [1913 Webster]
"I made virtue of necessity." [1913 Webster]
"In the Greek poets, . . . the economy of poems is better observed than in Terence, who thought the sole grace and virtue of their fable the sticking in of sentences." [1913 Webster]

5.  Specifically, moral excellence; integrity of character; purity of soul; performance of duty. [1913 Webster]
"Virtue only makes our bliss below." [1913 Webster]
"If there's Power above us,
And that there is all nature cries aloud
Through all her works, he must delight in virtue." [1913 Webster]

6.  A particular moral excellence; as, the virtue of temperance, of charity, etc. [1913 Webster]

7.  Specifically: Chastity; purity; especially, the chastity of women; virginity. [1913 Webster]
"H. I believe the girl has virtue.
M. And if she has, I should be the last man in the world to attempt to corrupt it." [1913 Webster]

8.  One of the orders of the celestial hierarchy. [1913 Webster]
"Thrones, dominations, princedoms, virtues, powers." [1913 Webster]

virtue, n.
1 moral excellence; uprightness, goodness.
2 a particular form of this (patience is a virtue).
3 chastity, esp. of a woman.
4 a good quality (has the virtue of being adjustable).
5 efficacy; inherent power (no virtue in such drugs).
6 an angelic being of the seventh order of the celestial hierarchy (see ORDER n. 19).

Idiom:
by (or in) virtue of on the strength or ground of (got the job by virtue of his experience). make a virtue of necessity derive some credit or benefit from an unwelcome obligation.

Derivative:
virtueless adj.

Etymology:
ME f. OF vertu f. L virtus -tutis f. vir man

N  goodness, excellence, merit, virtue, value, worth, price, super-excellence, supereminence, superiority, perfection, coup de maitre, masterpiece, chef d'ouvre, prime, flower, cream, elite, pick, A, nonesuch, nonpareil, creme de la creme, flower of the flock, cock of the roost, salt of the earth, champion, prodigy, tidbit, gem, gem of the first water, bijou, precious stone, jewel, pearl, diamond, ruby, brilliant, treasure, good thing, rara avis, one in a thousand, beneficence, good man, harmless, hurtless, unobnoxious, innocuous, innocent, inoffensive, beneficial, valuable, of value, serviceable, advantageous, edifying, profitable, salutary, favorable, propitious fair, good, good as gold, excellent, better, superior, above par, nice, fine, genuine, best, choice, select, picked, elect, recherche, rare, priceless, unparagoned, unparalleled, superlatively, good, bully, crackajack, giltedged, superfine, superexcellent, of the first water, first-rate, first-class, high- wrought, exquisite, very best, crack, prime, tiptop, capital, cardinal, standard, inimitable, admirable, estimable, praiseworthy, pleasing, couleur de rose, precious, of great price, costly, worth its weight in gold, worth a Jew's eye, priceless, invaluable, inestimable, precious as the apple of the eye, tolerable, up to the mark, unexceptionable, unobjectionable, satisfactory, tidy, in good condition, in fair condition, fresh, sound, beneficially, well, Jewels five words long, long may such goodness live!, the luxury of doing good.

N  purity, decency, decorum, delicacy, continence, chastity, honesty, virtue, modesty, shame, pudicity, pucelage, virginity, vestal, virgin, Joseph, Hippolytus, Lucretia, Diana, prude, pure, undefiled, modest, delicate, decent, decorous, virginibus puerisque, simon-pure, chaste, continent, virtuous, honest, Platonic, virgin, unsullied, cherry, as chaste as unsunn'd snow, a soul as white as heaven, 'tis Chastity, my brother, Chastity, to the pure all things are pure.

N  power, potency, potentiality, jiva, puissance, might, force, energy, dint, right hand, right arm, ascendency, sway, control, prepotency, prepollence, almightiness, omnipotence, authority, strength, ability, ableness, competency, efficacy, efficiency, productivity, expertise (skill), validity, cogency, enablement, vantage ground, influence, pressure, conductivity, elasticity, gravity, electricity, magnetism, galvanism, voltaic electricity, voltaism, electromagnetism, atomic power, nuclear power, thermonuclear power, fuel cell, hydraulic power, water power, hydroelectric power, solar power, solar energy, solar panels, tidal power, wind power, attraction, vis inertiae, vis mortua, vis viva, potential energy, dynamic energy, dynamic friction, dynamic suction, live circuit, live rail, live wire, capability, capacity, quid valeant humeri quid ferre recusent, faculty, quality, attribute, endowment, virtue, gift, property, qualification, susceptibility, powerful, puissant, potential, capable, able, equal to, up to, cogent, valid, efficient, productive, effective, effectual, efficacious, adequate, competent, multipotent, plenipotent, omnipotent, almighty, forcible, (energetic), influential, productive, powerfully, by virtue of, by dint of, a toute force, dos moi pou sto kai kino ten gen, eripuit coelo fulmen sceptrumque tyrannis, fortis cadere cedere non potest.

N  courage, bravery, valor, resoluteness, boldness, spirit, daring, gallantry, intrepidity, contempt of danger, defiance of danger, derring-do, audacity, rashness, dash, defiance, confidence, self-reliance, manliness, manhood, nerve, pluck, mettle, game, heart, heart of grace, spunk, guts, face, virtue, hardihood, fortitude, intestinal fortitude, firmness, heart of oak, bottom, backbone, spine, resolution, bulldog courage, prowess, heroism, chivalry, exploit, feat, achievement, heroic deed, heroic act, bold stroke, man, man of mettle, hero, demigod, Amazon, Hector, lion, tiger, panther, bulldog, gamecock, fighting-cock, bully, fire eater, courageous, brave, valiant, valorous, gallant, intrepid, spirited, spiritful, high-spirited, high-mettled, mettlesome, plucky, manly, manful, resolute, stout, stout-hearted, iron-hearted, lion-hearted, heart of oak, Penthesilean, bold, bold-spirited, daring, audacious, fearless, dauntless, dreadless, aweless, undaunted, unappalled, undismayed, unawed, unblanched, unabashed, unalarmed, unflinching, unshrinking, unblanching, unapprehensive, confident, self-reliant, bold as a lion, bold as brass, enterprising, adventurous, venturous, venturesome, dashing, chivalrous, soldierly, heroic, fierce, savage, pugnacious, strong-minded, hardy, doughty, firm, determined, dogged, indomitable, up to, up to the scratch, upon one's mettle, reassured, unfeared, undreaded, one's blood being up, courage sans peur, fortes fortuna adjuvat, have I not in my time heard lions roar, I dare do all that may become a man, male vincetis sed vincite, omne solum forti patria, self-trust is the essence of heroism, stimulos dedit oemula virtus, strong and great, a hero, teloque animus proestantior omni, there, is always safety in valor, virtus ariete fortier.

N  right, what ought to be, what should be, fitness, summum jus, justice, equity, equitableness, propriety, fair play, impartiality, measure for measure, give and take, lex talionis, Astraea, Nemesis, Themis, scales of justice, evenhanded justice, karma, suum cuique, clear stage, fair field and no favor, level playing field, morals, law, honor, virtue, right, good, just, reasonable, fit, equal, equable, equatable, evenhanded, fair, legitimate, justifiable, rightful, as it should be, as it ought to be, lawful deserved, rightly, +a bon droit, au bon droit, in justice, in equity, in reason, without distinction of persons, without regard to persons, without respect to persons, upon even terms, Int, all right!, fair's fair, Dieu et mon droit, in equal scale weighing delight and dole, justitia cuum cuique distribuit, justitiae soror incorrupta fides, justitia virtutem regina, thrice is he armed that hath his quarrel just.

N  virtue, virtuousness, morality, moral rectitude, integrity, nobleness, morals, ethics, cardinal virtues, merit, worth, desert, excellence, credit, self-control, self-denial, well-doing, good actions, good behavior, discharge of duty, fulfillment of duty, performance of duty, well-spent life, innocence, virtuous, good, innocent, meritorious, deserving, worthy, desertful, correct, dutiful, duteous, moral, right, righteous, right- minded, well-intentioned, creditable, laudable, commendable, praiseworthy, above all praise, beyond all praise, excellent, admirable, sterling, pure, noble, whole-souled, exemplary, matchless, peerless, saintly, saint-like, heaven-born, angelic, seraphic, godlike, virtuously, adj, e merito, esse quam videri bonus malebat, Schonheit vergeht Tugend besteht, virtue the greatest of all monarchies, virtus laudatur et alget, virtus vincit invidiam.

by virtue of, cardinal virtue, natural virtue, supernatural virtue, theological virtue