stroppy (adj.)

"rebellious," by 1943, British nautical slang, perhaps a slang mangling of obstreperous. "Sea Passages: A Naval Anthology and Introduction to the Study of English" [1943, Geoffrey Callender] quotes from a letter:

Why Nobby should reckon that his raggie should blow the gaff, when there are crushers everywhere, leaves me guessing; but there it is. In the last dog he rounded on me and called me a white rat. I got stroppy and told him he was shooting a line: but all he said was, 'Oh! choke your luff! I'm looking for another oppo you snivelling sand-catcher.' So that looks like paying off.

to which Callender adds, "There is nothing in this letter which an active service rating could fail to understand."