Snatch, beaver, pussy, rabbit, fanny, box, bush etc. are all synonyms for that 'thing' that we don't want to name directly. From now on I'm just going to call it a 'synonym' and have done with it!
It sounds quite acceptable too, e.g. "I've just seen Pamela Anderson's synonym". "Britney Spears flashed her synonym when she was getting out of a car." "My head has got less hair on it than the average synonym." Most of MU's synonyms are going down to London for the Arsenal match"