Acronym: Missing Presumed Pissed: Used when persons do not show at work at the appointed time when there is no reasonable excuse other than excessive alcohol intake the previous night. Also used for any other inexplicable absence. The only valid excuse for tardiness. The term has a close association with being "As pissed as a mattress" ie having visited an establishment where "I know a place where they have food" or is otherwise skanky.
"Four drinking last night, and only one MPP ... Guess who?"
"How many MPP today?"
"Is Homer MPP?"
"Suomi boy has never been MPP ... yet"
"MPP? ... OOH, La-di-da"