Main Entry: ker·nel

Pronunciation: \ˈkər-n^əl\

Function: noun

Etymology: Middle English, from Old English cyrnel, diminutive of corn

Date: before 12th century

1 chiefly dialect : a fruit seed
2 : the inner softer part of a seed, fruit stone, or nut
3 : a whole seed of a cereal <a kernel of corn>
4 : a central or essential part : germ <like many stereotypes…this one too contains some kernels of truth — S. M. Lyman>
5 : a subset of the elements of one set (as a group) that a function (as a homomorphism) maps onto an identity element of another set