Noun: A slink can be many things, but all relating to creepiness or promiscuity. An animal can be a slink if they are a "slinkety" creature, which involves having an arched back, and moving as if they were crawling and gliding at the same time (eg. ferret, weasel, mink). A person, typically a female, can be a slink, if they tend to engage in sexual behavior that would be frowned upon by ones parents, or the good of society.
Verb: Slinking is a wave like motion often created by animals with fur, and arched backs like the ever so popular ferret. They move about creepily, often curling up their backs while scampering around sneakily.
Noun: "That girl in that see through shirt looked like such a slink!"
Verb: "Did you see the ferrets at the pet store slinking around? They were really great to watch."