the choicest or most essential or most vital part of some idea or experience
"the gist of the prosecutor's argument"
"the heart and soul of the Republican Party"
"the nub of the story"
The core, center, or essence of an object or system.
In plain English: A kernel is the core part of an operating system that manages all the computer's hardware and software resources.
"She carefully removed the hard kernel from the ear of corn before eating it."
Usage: Use "kernel" to describe the essential core or most important part of a subject, such as the kernel of truth in a story. Do not confuse it with the outer shell or non-essential details surrounding that central idea.
To enclose within a kernel
"The ancient fortification was designed to keep the invading army safely enclosed within its outer wall, much like a seed is protected inside its hard shell."
In plain English: To kernel something means to remove the hard center part of it, like popping corn out of its shell.
"The developer will kernel the new software features before releasing the update."
Usage: Do not use "kernel" as a verb to mean enclose something; that definition is archaic and rarely used in modern English. Instead, treat "kernel" strictly as a noun referring to the seed or core of something, and use verbs like "encase" or "wrap" if you need to describe enclosing an object.
The word "kernel" comes from Old English cyrnel, which originally meant a seed or grain. It is derived from the Proto-Germanic root for "seed," combined with a suffix that indicates smallness.