rat

noun

1.
any of various long-tailed rodents similar to but larger than a mouse
Derived from:
rat ratty
2.
someone who works (or provides workers) during a strike
Derived from:
rat
4.
one who reveals confidential information to the police or other authority
Derived from:
rat
5.
a pad (usually made of hair) worn as part of a woman's coiffure
Derived from:
rat