kärna
Kärna is a Swedish noun with several related senses centered on the idea of a central part or seed. The primary meanings are: the core or central part of something; the edible seed or stone inside a fruit (for example äpplets kärna); and by extension the kernel in computing or in mathematics, i.e., the essential or underlying part of a system, function, or morphism. As a verb, kärna means to remove the core or seed from a fruit (to core), or more generally to remove the essential part from something.
In biology, the word appears in fixed compounds such as cellkärna, meaning the nucleus of a cell;
Etymology: kärna comes from Old Swedish and is cognate with Norwegian kjerne and Danish kerne; all reflect