zonkhttp://www.oed.com/dictionary/zonk_int%3Ftab%3Dmeaning_and_usezonk, int.
First published 1986; not fully revised

zonkinterjection (& noun)

slang.
  1. 1949–
    Representing the sound of a blow or heavy impact, used to indicate finality. Occasionally as n. (see quots.).
    1. 1949
      Just sit there and relax and I'll dash and get you an enormous zonk of whisky.
      T. Rattigan, Harlequinade 38
    2. 1958
      I..hurl it with a great zonk into the waste-paper basket.
      Spectator 15 August 218/2
    3. 1961
      I never took a note when I was interrogating. The moment you got hold of a piece of paper they'd think ‘ah-hah..’ and zonk! they'd button up.
      Radio Times 16 November 47/2
    4. 1968
      Silas..closed the safe door a few times. Zonk. It closed with a clang.
      L. Deighton, Only when I Larf i. 12
    5. 1979
      He was a man with a catapult. He'd knock a pheasant down—zonk!
      R. Blythe, View in Winter i. 64

zonk, int. was first published in 1986; not fully revised.

zonk, int. was last modified in July 2023.