The Collaborative International Dictionary of English v.0.48:

Tetchy \Tetch"y\, a.
   See Techy. --Shak.
   [1913 Webster]

WordNet (r) 3.0 (2006):

tetchy
    adj 1: easily irritated or annoyed; "an incorrigibly fractious
           young man"; "not the least nettlesome of his countrymen"
           [syn: cranky, fractious, irritable, nettlesome,
           peevish, peckish, pettish, petulant, scratchy,
           testy, tetchy, techy]

Moby Thesaurus II by Grady Ward, 1.0:

40 Moby Thesaurus words for "tetchy":
   allergic, anaphylactic, cantankerous, choleric, cranky, cross,
   delicate, empathetic, empathic, goosy, high-strung, hyperesthetic,
   hyperpathic, hypersensitive, ill-humored, irritable, itchy, miffy,
   nervous, overrefined, oversensible, oversensitive, overtender,
   passible, prickly, quick-tempered, ratty, refined, responsive,
   sensitive, skittish, supersensitive, sympathetic, tactful,
   temperamental, tender, testy, thin-skinned, ticklish, touchy