[ 'kə:n(ə)l ]
■ noun
1》 a softer part of a nut, seed, or fruit stone contained within its hard shell.
↘the seed and hard husk of a cereal, especially wheat.
2》 the central or most important part of something.
↘ Computing the most basic level or core of an operating system.
Origin
OE cyrnel , dimin. of corn 1 .