a very offensive curse word

The horrible moment when you realise that you have accidentally done something very slightly wrong which has very bad (usually embarassing) implications for you. This is typically the moment of realisation that you just sent a dirty text message to a close member of family, typically your mother, rather than the intended recipient.

The only word on this site that has nothing to do with sex or drugs!

It's a form of salutation of greeting in the English language, aslo used at telephone.

1. A form of greeting used in reference to multiple individuals.
2. An abreviation of "Hello, hello, hello!" used to make the speaker appear less annoying.

what you say when your talking casually with friends and your mom walks in the room

A greeting used when first seeing somebody.