Kernel

chicco

(single seed of corn or wheat)

gheriglio

(central part of a nut)

kernel

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

nocciolo

(core or essence of an object or system)

nocciolo

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

nucleo

(core or essence of an object or system)

nucleo

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