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1.
Adjective used to describe people, typically but not necessarily female, who are both overweight and promiscuous. A portmanteau of the words slutty and pudgy.
Ed: Man, that girl is sludgy.
Gary: Yeah, she's 250 pounds and has sex with random strangers.
by F-squared June 11, 2008
 
2.
Similar to Slimy in the sense that it is used to describe a male who tries to become 'good friends' with other people's girlfriends, however in a Sludgy case, the girls themselves realise that he has more slimy intentions, whereas slimy guys manage to avoid the detection of their victims.
boy1) Pete is so slimy man...
boy2) nah hes actually so slimy he's sludgy - even she can tell.

girl 1) yeah he's such a sludge.
by antislime February 23, 2011