Same word as zealous:

afire, antsy, ardent, avid, burning, coming on strong, dedicated, devoted, eager, earnest, fanatic, fanatical, fervent, fervid, fireball, fired, frenetic, gung-ho, hot, impassioned, itchy, keen, obsessed, passionate, possessed, pushy, rabid, ripe, self-starting, spirited, wild-eyed