2. adj. A person who frequently plans things and does not show up, or never answers calls, emails, etc.
"kr*sten G*****s? stokes ur 'greggin', there's no way u got with that trick"
Greg is a drink. It is also used to describe a person that is drinking the drink.
gregged someone that has drunk too much
Do you want a Greg?
Greg You were so gregged last night? How much did you have to greg