Real Dictionary

avocado
variable noun: Avocados are pear-shaped vegetables, with hard skins and large stones, which are usually eaten raw.

avocado in American English
a widespread, thick-skinned, pear-shaped tropical fruit, yellowish green to purplish black, with a single large seed and yellow, buttery flesh, used in salads; alligator pear
noun: a large, usually pear-shaped fruit having green to blackish skin, a single large seed, and soft, light-green pulp, borne by the tropical American tree Persea americana and its variety P. adrymifolia, often eaten raw, esp. in salads

avocado in British English
noun: a pear-shaped fruit having a leathery green or blackish skin, a large stony seed, and a greenish-yellow edible pulp