adjective: Easily annoyed; oversensitive.
Of uncertain origin. Perhaps from Middle English tache/teche (blemish). Earliest documented use: 1597.
“O comes across as tired and tetchy, and fed up with being unfairly treated by the press.”
So Who Wrote O?; Daily Mail (London, UK); Jan 21, 2011.
Explore “tetchy” in the Visual Thesaurus.