adjective
tetchy
TECH-ee/ˈtetʃi/
Easily annoyed or irritated.
The tetchy man scowls impatiently at a tiny splash of coffee.

Etymology
The word is recorded with the meaning 'easily irritated,' but its origin is uncertain. The related noun tetch, 'a tantrum,' appears later and may have been formed from the adjective.
In context
even though he was allowed to get away with telling blatant lies he still got very tetchy he's got really frustrated at being asked questions
More examples
- I'm a little tetchy today because I barely slept.
- She grew tetchier as the questions continued.
- His tetchy reply made me hesitate to ask for help.
Forms
tetchy · tetchier · tetchiest
tetchiness noun — The tendency to become easily irritated.
tetchily adverb — In an easily annoyed or irritated manner.