to go behind someone's back

A word used when referring to a friend or companion.

a companion, friend, homie

Australian slang for police informant.

Australian Slag for being 'Ditched' or 'Ditching'
You would say 'Dont Dog it' or 'They Dogged it'

And if a person did something bad to someone els,
or had plans with someone, and didnt show..
they did a 'Dog act'

If someone just isnt a nice person..
or is known to 'Ditch' people, they are known as 'Dogs'

The word dog is Used to describe something that is awful

Heroin, Also know as dog food