cock a snook at somebody/something

cock a snook

To regard someone or something with disrespect. Primarily heard in UK. Don't you cock a snook at my instructions—I'm your superior!
See also: cock, snook
Farlex Dictionary of Idioms.

cock a snook at someone

to show or express defiance or scorn at someone. He cocked a snook at the traffic cop and tore up the ticket. The boy cocked a snook at the park attendant and walked on the grass.
See also: cock, snook
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs.

cock a snook

Thumb one's nose, as in As soon as the teacher turned her back, the boys cocked a snook at her. This expression was first recorded in 1791 and the precise source of snook, here used in the sense of "a derisive gesture," has been lost. It is more widely used in Britain but is not unknown in America.
See also: cock, snook
The American Heritage® Dictionary of Idioms by Christine Ammer.

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 .
See also: cock, snook
Farlex Partner Idioms Dictionary

cock a ˈsnook at somebody/something

(British English, informal)
1 make a rude gesture by putting your thumb to your nose
2 do or say something that shows your lack of respect for somebody/something, especially when you cannot be punished for this: She cocked a snook at her teachers by going to school with her hair dyed purple.
See also: cock, snook, somebody, something
Farlex Partner Idioms Dictionary
See also:
  • cock a snook
  • cock a snook at
  • cock a snook at someone/something
  • snook
  • snoot
  • cock a
  • cock a snoot
  • cock (one's) ear
  • cock your ear
  • cock socket