niche. Smallest unit of a habitat that is occupied by an organism. A habitat niche is the physical space occupied by the organism; an ecological niche is the role the organism plays in the community of organisms found in the habitat. Nothing to do with word smart whatsoever. Used was used metaphorically. I agreed I said something wrong, but I apparently I didn't. You don't know what you were talking about. Over and out. Don't bother answering, as you are attacking my words and not my idea, where idea is clearly given.