'challenger' originates from Middle English, specifically from the word 'chalenge' (borrowed earlier from Old French 'chalenge'), where the agentive suffix '-er' indicated 'a person who performs the action'.

'challenger' developed from Old French 'chalenge' / Middle English 'chalenger' and eventually became the modern English word 'challenger' by the regular addition of the agentive suffix '-er' to the verb 'challenge'.

Initially it referred broadly to someone who accused or challenged (in the sense of dispute); over time it came to mean specifically 'one who contests a title or opposes an incumbent' as well as 'one who questions authority or accepted ideas'.