irritable(adjective) adjective1. easily irritated or annoyedSimilar word(s): cranky, fractious, nettlesome, peckish, peevish, pettish, petulant, scratchy, techy, testy, tetchy2. abnormally sensitive to a stimulusSimilar word(s): sensitive3. capable of responding to stimuliSimilar word(s): sensitive, excitable