1.  athletic(a = adj.pert) - relating to or befitting athletics or athletes; "athletic facilities"
Derived form noun athlete₁

2.  athletic(s = adj.all) acrobatic, gymnastic - vigorously active; "an acrobatic dance"; "an athletic child"; "athletic playing"; "gymnastic exercises"
Derived form noun athletics₁

3.  athletic(s = adj.all) - having a sturdy and well proportioned body; "an athletic build"

1.  Of or pertaining to athletes or to the exercises practiced by them; as, athletic games or sports. [1913 Webster]

2.  Befitting an athlete; strong; muscular; robust; vigorous; as, athletic Celts. [1913 Webster]

athletic, adj.
1 of or relating to athletes or athletics (an athletic competition).
2 muscular or physically powerful.

Derivative:
athletically adv. athleticism n.

Etymology:
F athl{eacute}tique or L athleticus f. Gk athletikos (as ATHLETE, -IC)

N  strength, power, energy, vigor, force, main force, physical force, brute force, spring, elasticity, tone, tension, tonicity, stoutness, lustihood, stamina, nerve, muscle, sinew, thews and sinews, physique, pith, pithiness, virtility, vitality, athletics, athleticism, gymnastics, feats of strength, adamant, steel, iron, oak, heart of oak, iron grip, grit, bone, athlete, gymnast, acrobat, superman, Atlas, Hercules, Antaeus, Samson, Cyclops, Goliath, tower of strength, giant refreshed, strengthening, invigoration, refreshment, refocillation, dynamics, statics, strong, mighty, vigorous, forcible, hard, adamantine, stout, robust, sturdy, hardy, powerful, potent, puissant, valid, resistless, irresistible, invincible, proof against, impregnable, unconquerable, indomitable, dominating, inextinguishable, unquenchable, incontestable, more than a match for, overpowering, overwhelming, all powerful, all sufficient, sovereign, able-bodied, athletic, Herculean, Cyclopean, Atlantean, muscular, brawny, wiry, well-knit, broad-shouldered, sinewy, strapping, stalwart, gigantic, manly, man-like, manful, masculine, male, virile, unweakened, unallayed, unwithered, unshaken, unworn, unexhausted, in full force, in full swing, in the plenitude of power, stubborn, thick-ribbed, made of iron, deep-rooted, strong as a lion, strong as a horse, strong as an ox, strong as brandy, sound as a roach, in fine feather, in high feather, built like a brick shithouse, like a giant refreshed, strongly, by force, by main force, our withers are unwrung, Blut und Eisen, coelitus mihi vires, du fort au diable, en habiles gens, ex vi termini, flecti non frangi, he that wrestles with us strengthens our nerves an, inflexible in faith invincible in arms.

athletic competition, athletic contest, athletic facility, athletic field, athletic game, athletic sock, athletic supporter, athletic training, athletic type, athletic wear