- 1. the sexual attractiveness of females as perceived by malesA survival from the 1930s prudery about sex:'It is not beauty that makes every head (except one) turn on the beach to look at her.' 'It's IT, my boy,' said the Major. (Christie, 1940)2. copulationA usage without any prior reference to the subject matter:I would have asked you anyway... you see, I like it with you. (Bradbury, 1976)3. the male or female genitalsAgain, the subject has not been previously introduced:Whereas in Jake's youth he had gawped at a girl with upper clothing disarranged to reveal a, to him, rare glimpse of 'them', he is now horrified to find himself staring much lower down at a sharply focussed full-colour close-up of 'it'. (F. Muir, 1990, writing of K. Amis's Jake's Thing)
How not to say what you mean: A dictionary of euphemisms. R. W. Holder. 2014.