The Collaborative International Dictionary of English v.0.48:
zestful \zest"ful\ (z[e^]st"f[.u]l), adj. Marked by spirited enjoyment. Syn: yeasty, zesty. [WordNet 1.5]WordNet (r) 3.0 (2006):
zestful adj 1: marked by spirited enjoyment [syn: zestful, yeasty, zesty, barmy]