noun, plural: niches
(ecology) (1) The specific area where an organism inhabits.
(2) The role or function of an organism or species in an ecosystem.
(general) A cavity, hollow, or recess, especially in a wall.
In ecology, the definition of niche has changed overtime. Joseph Grinnell in 1917 coined the term niche, which he used as largely equivalent to a species habitat. In 1927, Charles Sutherland Elton regarded niche to be equivalent to the position of a species in a trophic web. In 1958, George Evelyn Hutchinson used the term niche to describe the multi-dimensional space of resources available to and used by a species.