n. A person who consumes an excessive amount of alcohol while standing up.
Other Forms
A new expression is coming into vogue in London — Male Vertical Volume Drinkers (MVVD). It seems these people do not take seats, be it in posh bars or popular pubs, but drink straight from the bottle, standing.
—K. Gopalan, “Idling man,” Business Line, February 13, 2003
2000 (earliest)
The youngsters who dominate the "night-strips" are known as MVVDs — mass volume vertical drinkers — because they are encouraged to stand in large groups, swigging from bottles.

MVVD drinking requires neither comfortable furniture nor staff to wash glasses and pull pints.
—Ian Burrell, “Planners and police surrender city centres to Britain's mass volume vertical drinkers,” The Independent (London), July 17, 2000
The abbreviation MVVD is short for male vertical volume drinker, although, as the earliest citation shows, mass volume vertical drinker is another possibility (as are the nonsensical variations male volume vertical drinker and mass vertical volume drinker).