challenger.

Inherited from Middle English chalengere, chalangeour, chalenger (“one who causes injury, or makes false charges or slanderous statements; one who disputes, disputant, objector; claimant”), and then partly from both of the following: * From Middle English chalengen (“to accuse; to accuse falsely or maliciously, slander; to treat unjustly, wrong; to dispute, object; to make a claim or demand; to rebuke, scold; to issue a challenge to; etc.”) + -er, -ere (suffix forming agent nouns). Chalengen is derived from Anglo-Norman chalenger, and Old French chalenger, chalongier (“to challenge, dispute; to claim; etc.”) (modern French challenger), from Late Latin calumniāre, the second-person singular present active imperative or indicative of calumnior (“to accuse falsely; to make hurtful untrue comments about; etc.”), from Latin calumnia (“artifice, trickery; false accusation; false statement; etc.”) (ultimately from Proto-Indo-European *ḱeh₁l-, *keh₁l- (“to beguile, deceive”)) + -or (the first-person singular present passive indicative of -ō (suffix forming regular first-conjugation verbs)). * From Old French chalengeor (“claimant, plaintiff; false accuser, slanderer”) (modern French challengeur), from chalenger, chalongier (see above) + -eor (variant of -or (suffix forming agent nouns)). By surface analysis, challenge (verb) + -er (suffix forming agent nouns).