1. the soft inner part of a nut, seed, or fruit pit
2. a grain or seed, especially of corn
3. the central or most important part of something

Examples

• She cracked the walnut to get to the kernel inside.
• Each kernel of corn popped in the hot oil.
• The kernel of his argument was that taxes should be lowered.
• There’s a kernel of truth in what she’s saying.
• The operating system kernel handles memory management.
• Popcorn kernels need high heat to pop properly.