n.

1. （果核或果殼內的）仁[C]
2. （麥、玉米等的）粒，子[C]
3. 【喻】核心，要點[the S][（+of）]
   the true kernel of the matter

   這件事的真正核心

vt.

1. 把……包在核（或殼）內；把……作核心

n.

1. a softer part of a nut, seed, or fruit stone contained within its hard shell.
   ▸the seed and hard husk of a cereal, especially wheat.
2. the central or most important part of something.
   ▸Computing  the most basic level or core of an operating system.