anal sex but in slang terms can be used :
1. As a term of abuse for someone or something contemptible, difficult or unpleasant.
2. Affectionately, as in 'you silly bugger'.
3. As an exclamation of dissatisfaction, annoyance or surprise.
4. To mean tired or worn out as in 'I'm absolutely buggered'.
5. To mean frustrate, complicate or ruin completely, as in 'You've buggered that up'.