very angry or easily annoyed
choleric - angry
A person described as ‘choleric’ is considered irritable and short-tempered. Having this character trait of being quick to anger (with or without justification) generally makes a person unpopular in a social environment, and a liability professionally, especially if their job involves dealing with customers.
Watch out for the choleric person on reception. She is rude and tetchy to everyone.
Gary shouldn’t be interacting with customers. Such work does not suit his choleric disposition.
It’s hard to know where you stand with Alice. She can be relaxed and affable one moment, and then choleric the next.