Synonyms for Sappy (same or very similar meaning)
WordNet sense 1 (ludicrous, foolish):
cockamamie, goofy, silly, wacky, zany, cockamamy, whackyWordNet sense 2 (devoid of good sense or judgment):
foolishWordNet sense 3 (full of juice):
juicyFrom the ODE community, based on WordNetadd/edit