(adj.) Dirty, possibly skanky, almost hobo-like. Characterized by poor personal hygiene or sexual laxness. A custy person will often stoop to any act of debasement in exchange for money, food, drugs, or other superficial rewards.
(n.) A person who is custy (see above).
"She didn't even know the guy and she gave him a rimjob
? That's custy."
"Did you see that custy? She offered to suck me for half a gram of shitty weed!"
"Ew, don't touch me, you custy freak."