[monged (out)] {adj.} Severely drunk/high.

[moniker or monicker] {n.} Name, nickname, signature or mark.

[monkey] {n.} £500.

[mooch] {v.} Loiter or wander aimlessly, skulk.

[moolah] {n.} Money.

[moon] {v.} To expose one's backside (from Old English, mona).

[moony] Crazy or foolish. {adj.}

[muck about] {v.} Waste time. Interfere with.

[muck in] {v.} Share a duty or workload.

[mucker] {n.} Mate, pal.