kernel

noun

• 1a softer, usually edible part of a nut, seed, or fruit stone contained within its shell: the kernel of a walnut pine kernels
• the seed and hard husk of a cereal, especially wheat: the milky kernel of the wheat grain

• 2the central or most important part of something:this is the kernel of the argument
• Computing the most basic level or core of an operating system, responsible for resource allocation, file management, and security.
• [as modifier] Linguistics denoting a basic unmarked linguistic string.