testy
Concise Oxford English Dictionary © 2008 Oxford University Press:
testy/ˈtesti/
▶adjective (testier, testiest) irritable.
– derivatives
testily adverb,
testiness noun.
testily adverb,
testiness noun.
– origin ME (in the sense ‘headstrong, impetuous’): from Anglo-Norman Fr. testif, from OFr. teste ‘head’, from L. testa ‘shell’.
'testy' also found in these Oxford entries:

