Antonyms for lazy

inactive, sluggish:

attentive, fresh, careful, industrious, hard-working, caring, interested, vivacious, energetic, concerned, lively, diligent, activated, active.

noun:

concerned, interested, busy, forethoughtful, regarding, occupied, regardful, thinking, gingerly, guarded, wary, thoughtful, attentive, heedful, foresighted, watchful, cautious, fast, chary, zealous, working, provident, mindful, vigilant, responsible, circumspect, observant, exuberant, punctilious, enterprising, employed.