infight

Meaning

Verb

1. To fight with allies or other members of the same group.
2. To box while extremely close to an opponent

Noun

An internal battle; a fight with allies or other members of the same group.

Etymology

Apparently a back-formation from infighting, perhaps continuing Middle English infighten (“to attack”), from Old English infiht, infeoht (“an attack made upon a person by another in the same house or between members of a household”), equivalent to in- + fight.