noun
1.
an ornamental recess in a wall or the like, usually semicircular in plan and arched, as for a statue or other decorative object.
2.
a place or position suitable or appropriate for a person or thing:
to find one's niche in the business world.
3.
a distinct segment of a market.
4.
Ecology. the position or function of an organism in a community of plants and animals.
adjective
5.
pertaining to or intended for a market niche; having specific appeal:
niche advertising.
verb (used with object), niched, niching.
6.
to place (something) in a niche.