Definition of niches:
(n) :
(by extension) Any position of opportunity for which one is well-suited, such as a particular market in business.
(n) :
Any similar position, literal or figurative.
(n) :
(ecology) A function within an ecological system to which an organism is especially suited.
(n) :
(architecture) A cavity, hollow, or recess, generally within the thickness of a wall, for a statue, bust, or other erect ornament.
(adj) :
Pertaining to or intended for a market niche; having specific appeal; obscure.
(v) :
(transitive) To place in a niche.