Basically the London slang used for 'head' (uck/ucky)

It's the sweat that accumilates under big boobs

A gross or disgusting situation or substance.

Poop, Shit,

the nasty scum and smell on your sponge after cleaning the week old dishes

This word is used interchangably (and equally effectively) as both a noun and an adjective. An "uck" or "ucky" is someone who is portraying more than the usual amount of maliciousness, selfishness, butt-headedness, or just down right stupidity. A person can be described as "ucky," but does not quite qualify for the "uck" status. "Ucky-bucky" is the epitome of uckiness.