tetchy

Tetchy is a word that may have been coined by Shakespeare - its first known use in English occurs in Romeo and Juliet (1592). Etymologists are not certain how the word came about, but some have suggested that it derives from "tetch," an obsolete noun meaning "habit." The similarity both in meaning and pronunciation to "touchy" might lead you to conclude that "tetchy" is related to that word, but there is no conclusive evidence to suggest such a connection. The adjectives "teched" and tetched, meaning "mentally unbalanced," are variations of "touched," and are probably also unrelated to "tetchy."