Kernel

зърно́

zǎrnó

(single seed of corn or wheat)

костилка

kostilka

((US) stone of certain fruits, such as peaches or plums)

съ́щност

sǎ́štnost

(core or essence of an object or system)

я́дка

jádka

(central part of a nut)

ядро

jadro

((computing) central part of many computer operating systems)

ядро

jadro

((mathematics, algebra) set of elements mapped to zero)

ядро́

jadró

(core or essence of an object or system)