1. "not habitable," late 14c., from Old French inhabitable (14c.), from Latin inhabitabilis, from in- "not, opposite of" (see in- (1)) + habitabilis (see habitable).
2. "capable of being inhabited" (the main modern sense), c. 1600, from inhabit + -able). In Late Latin, inhabitabilis also was used in a sense of "that can be inhabited." A word used in two opposite senses.