core

the core of an apple or quince

Reindeer are well suited to the taiga’s frigid winters. They can maintain a thermogradient between body core and the environment of up to 100 degrees, in part because of insulation provided by their fur, and in part because of counter-current vascular heat exchange systems in their legs and nasal passages.

the core of the square

I wanted to play a particular computer game, which required I buy a new computer, so while the game said it needed at least a dual-core processor, I wanted my computer to be a bit ahead of the curve, so I bought a quad-core.

a floor panel with a Nomex honeycomb core

In a hollow-core design, neutrons escape from the core more readily, allowing more fissile material to be used (and thus allowing for a greater yield) while still keeping the core subcritical prior to detonation.

[the skin of the sheep] is clear from cores and jogs under the jaws.