The internal organs and parts of something, especially of an animal or machine.
From 'inward' (something inside) + '-s' suffix. It's a colloquial plural form that became standard, originally meaning the internal organs used in cooking.
Innards started as a cooking term—butchers and cooks needed a casual word for organs they were preparing. It spread metaphorically to machines ('the innards of a computer') showing how food vocabulary expands to new fields!
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