'beetle' originates from Old English, specifically the word 'bitela', where the root is likely from Proto-Germanic '*bitilōn' (a word for the insect).

'beetle' changed from Middle English forms such as 'beteel'/'betele' (borrowed from Old English 'bitela') and eventually became the modern English word 'beetle'.

Initially it referred to the insect (the Coleoptera); over time the word retained that meaning and was extended metaphorically to objects resembling the insect in shape or to large wooden hammers (the mallet meaning).