cock a snook openly show contempt or a lack of respect for someone or something. informal, chiefly British

☞ Literally, if you cock a snook, you place your hand so that your thumb touches your nose and your fingers are spread out, in order to express contempt. Recorded from the late 18th century, the expression's origins are uncertain-as are those of the gesture itself, which occurs under a variety of names and in many countries, the earliest definite mention of it being by Rabelais in 1532.