arch-rival
Primary sworn enemy
An arch-rival is a principal or chief rival—the one competitor who stands above all others in intensity or importance.
The prefix arch- signals supremacy, as in archenemy.
Sports teams have arch-rivals; so do politicians, businesses, and fictional heroes: Batman's arch-rival is the Joker.
The rivalry is usually long-standing and deeply felt.
Bitter ongoing rivalry
- grudgePersistent resentment toward someone
- hatredIntense hostile aversion
- enmityBitter, lasting ill will
- hostilityAntagonistic disposition toward others
bitterness · vendetta · bad blood · tension · animosity · spite · resentment · malice
Persistent source of ruin
- enemyHostile opposing party
- opponentOne who contends against
- foeHostile opponent
- antagonistOne who opposes another
competitor · challenger · contender · opposer · combatant · villain · counterpart · foil
feud
Bitter ongoing rivalry
- grudgePersistent resentment toward someone
- hatredIntense hostile aversion
- enmityBitter, lasting ill will
hostility · bitterness · vendetta · bad blood · tension · animosity · spite · resentment · malice · ill will
nemesis
Persistent source of ruin
antagonist · competitor · challenger · contender · opposer · combatant · villain · counterpart · foil · bane
matchup
Scheduled competitive pairing
- showdownDecisive final confrontation
- face-offDirect clash between opponents
- clashViolent disagreement or collision
contest · derby · duel · battle · fixture · rematch · head-to-head · playoffs · finals · championship
- rivalsopponent, adversary, competitor, foe, enemy
arch-rivalally
Supportive partner
best friend · partner · teammate · collaborator · confederate
arch-rivalnobody
Inconsequential person
nonentity · unknown · stranger · also-ran · afterthought