challenger
n. countablen. someone who competes against a person or team that is already successful or in power. You use this word for people trying to win a title or an election.
n. a person or group that competes against a current champion or office-holder. Often implies a serious attempt to displace the incumbent or established authority.
The young boxer is a strong challenger for the world title.
The mayor faces a tough challenger in the upcoming election who has strong support from local businesses.
Political analysts suggest that while the incumbent remains popular, a credible challenger from the progressive wing could significantly shift the debate during the primary season.
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).
Often paired with the preposition 'to' or 'for' ('a challenger to the throne', 'a challenger for the title').