1.  conscientious(s = adj.all) painstaking, scrupulous - characterized by extreme care and great effort; "conscientious application to the work at hand"; "painstaking research"; "scrupulous attention to details"
Derived form noun conscientiousness₂

2.  conscientious(a = adj.all) - guided by or in accordance with conscience or sense of right and wrong; "a conscientious decision to speak out about injustice"
Antonym: unconscientious
Derived forms noun conscience₂, noun conscience₃, noun conscientiousness₁

1.  Influenced by conscience; governed by a strict regard to the dictates of conscience, or by the known or supposed rules of right and wrong; -- said of a person. [1913 Webster]
"The advice of wise and conscientious men." [1913 Webster]

2.  Characterized by a regard to conscience; conformed to the dictates of conscience; -- said of actions. [1913 Webster]
"A holy and conscientious course."

conscientious, adj. (of a person or conduct) diligent and scrupulous.

Idiom:
conscientious objector a person who for reasons of conscience objects to conforming to a requirement, esp. that of military service.

Derivative:
conscientiously adv. conscientiousness n.

Etymology:
F consciencieux f. med.L conscientiosus (as conscience)

N  copy, facsimile, counterpart, effigies, effigy, form, likeness, image, picture, photo, xerox, similitude, semblance, ectype, photo offset, electrotype, imitation, model, representation, adumbration, study, portrait, resemblance, duplicate, reproduction, cast, tracing, reflex, reflexion, reflection, shadow, echo, transcript, transcription, recording, scan, chip off the old block, reprint, new printing, rechauffe, apograph, fair copy, parody, caricature, burlesque, travesty, travestie, paraphrase, derivative, derivation, modification, expansion, extension, revision, second edition, servile copy, servile imitation, plagiarism, counterfeit, fake, pasticcio, faithful, lifelike, close, conscientious, unoriginal, imitative, derivative.

N  duty, what ought to be done, moral obligation, accountableness, liability, onus, responsibility, bounden duty, imperative duty, call, call of duty, accountability, allegiance, fealty, tie engagement, part, function, calling, morality, morals, decalogue, case of conscience, conscientiousness, conscience, inward monitor, still small voice within, sense of duty, tender conscience, superego, the hell within, dueness, propriety, fitness, seemliness, amenability, decorum, to prepon, the thing, the proper thing, the right thing to do, the proper thing to do, ethics, ethology, deontology, aretology, moral philosophy, ethical philosophy, casuistry, polity, observance, fulfillment, discharge, performance, acquittal, satisfaction, redemption, good behavior, obligatory, binding, imperative, peremptory, stringent, behooving, incumbent on, chargeable on, under obligation, obliged by, bound by, tied by, saddled with, due to, beholden to, bound to, indebted to, tied down, compromised, in duty bound, amenable, liable, accountable, responsible, answerable, right, meet, moral, ethical, casuistical, conscientious, ethological, with a safe conscience, as in duty, bound, on one's own responsibility, at one's own risk, suo periculo, in foro conscientiae, quamdiu se bene gesserit, dura lex sed lex, dulce et decorum est pro patria mori, honos habet onus, leve fit quod bene fertur onus, loyaute m'oblige, simple duty bath no place for fear, stern daughter of the voice of God, there is a higher law than the Constitution.

N  probity, integrity, rectitude, uprightness, honesty, faith, honor, bonne foi, good faith, bona fides, purity, clean hands, fairness, fair play, justice, equity, impartiality, principle, even-handedness, grace, constancy, faithfulness, fidelity, loyalty, incorruption, incorruptibility, trustworthiness, truth, candor, singleness of heart, veracity, tender conscience, punctilio, delicacy, nicety, scrupulosity, scrupulousness, scruple, point, point of honor, punctuality, dignity, (repute), respectability, respectableness, gentilhomme, gentleman, man of honor, man of his word, fidus Achates, preux chevalier, galantuomo, truepenny, trump, brick, true Briton, white man, court of honor, a fair field and no favor, argumentum ad verecundiam, upright, honest, honest as daylight, veracious, virtuous, honorable, fair, right, just, equitable, impartial, evenhanded, square, fair and aboveboard, open and aboveboard, white, constant, constant as the northern star, faithful, loyal, staunch, true, true blue, true to one's colors, true to the core, true as the needle to the pole, marble-constant, true- hearted, trusty, trustworthy, as good as one's word, to be depended on, incorruptible, straightforward, frank, candid, open-hearted, conscientious, tender-conscienced, right-minded, high-principled, high-minded, scrupulous, religious, strict, nice, punctilious, correct, punctual, respectable, reputable, gentlemanlike, inviolable, inviolate, unviolated, unbroken, unbetrayed, unbought, unbribed, innocent, pure, stainless, unstained, untarnished, unsullied, untainted, unperjured, uncorrupt, uncorrupted, undefiled, undepraved, undebauched, integer vitae scelerisque purus, justus et tenax propositi, chivalrous, jealous of honor, sans peur et sans reproche, high-spirited, supramundane, unworldly, other-worldly, overscrupulous, honorable, bona fide, on the square, in good faith, honor bright, foro conscientiae, with clean hands, a face untaught to feign, bene qui latuit bene vixit, mens sibi conscia recti, probitas laudatur et alget, fidelis ad urnam, his heart as far from fraud as heaven from earth, loyaute m'oblige, loyaute n'a honte, what stronger breastplate than a heart untainted?.

conscientious objector