adjective
truculent
TRUHK-yuh-lunt/ˈtrʌkjələnt/
Hostile and ready to argue or fight.
The truculent customer argues with every employee who offers to help.

Etymology
Latin truculentus described fierceness, savagery, or harshness. The selected sense applies that ferocity to someone's manner: aggressively hostile or ready to argue.
In context
But he has a most truculent and overbearing manner--not at all the kind of manner you expect in a servant,
More examples
- His truculent tone turns a simple discussion into an argument.
- She grows truculent whenever anyone questions her decisions.
- The coach benches a truculent player for threatening an opponent.
Forms
truculent
truculence noun — A hostile readiness to argue or fight.
truculently adverb — In a hostile, aggressively defiant manner.
Similar words
- belligerent
- Emphasizes an openly aggressive readiness to fight or quarrel.
- combative
- Emphasizes eagerness to challenge or debate, not necessarily hostility.
- hostile
- Describes antagonism without necessarily suggesting readiness to argue or fight.