I'm not really sure, but maybe it is some sort of a greeting,pretty much related to the period of hippies ( wearing greasy hair and saying peace greeting smb or as a form of saying good bye)
-Hey man, peace! How's everything?
-Peace and hair grease, man.
The Urban Dictionary Mug
One side has the word, one side has the definition. Microwave and dishwasher safe. Lotsa space for your liquids.
Buy the mug