'badger' originates from Middle English, specifically the word 'bageard' (also spelled 'bagard' or 'bagearde'), where 'bage' referred to a 'badge' or white facial marking and the agent suffix (such as '-ard' or '-er') formed the noun for the animal.

'badger' changed from Middle English 'bageard' (a name associated with the animal's white 'badge') into Early Modern English as the standard name for the animal; the verb sense 'to badger' (to harass or pester) arose later from figurative use of the noun or from practices associated with baiting or forcing badgers.

Initially, it meant 'the animal named for its badge (white facial marking)' (and in some older uses a person associated with badges); over time it evolved a figurative verb meaning 'to pester or harass persistently' while retaining the original noun sense.