The Collaborative International Dictionary of English v.0.48:
Unripe \Un*ripe"\, a. 1. Not ripe; as, unripe fruit. [1913 Webster] 2. Developing too early; premature. --Sir P. Sidney. [1913 Webster]WordNet (r) 3.0 (2006):
unripe adj 1: not fully developed or mature; not ripe; "unripe fruit"; "fried green tomatoes"; "green wood" [syn: green, unripe, unripened, immature] [ant: mature, ripe] 2: not fully prepared