'ruminate' originates from Latin, specifically the word 'ruminare', where 'rumen' meant 'throat' or 'gullet' and 'ruminare' meant 'to chew over or chew the cud'.

'ruminate' changed from Late Latin 'ruminare' (lit. 'to chew the cud') and entered English via learned usage in the 16th–17th centuries, later expanding metaphorically to mean 'to ponder'.

Initially, it meant 'to chew the cud' (literal action of ruminant animals), but over time it evolved into its current meaning of 'to think deeply or ponder'.