a seed (of a fruit, nut, berry, or the like)
a seed, a pip (small, hard seed)
(ux)
a pit, a stone (in a drupe, avocado, or the like)
a kernel (edible seed)
a kernel, a nucleus, a core (central or most important part)
a kernel (operating system kernel)
a churn (a vessel used for churning, especially for producing butter)
to churn