Pronounced "trowned", it simply describes the deepness and magnitude of how owned someone has been. It can also represent the constant amount of owning or the owning in the quantity of '3'. It's origins come from the french word 'trois' meaning three and combining it with 'wned' (the suffix of 'owned').
Guy 1: dude, you got owned! i just completely annihalated you!
Guy 2: that may be, but i 3wned you last night when i murked you 3 times!!!