rat

Sense 1 noun

any of various long-tailed rodents similar to but larger than a mouse

Sense 2 verb

desert one's party or group of friends, for example, for one's personal advantage

Sense 3 noun

someone who works (or provides workers) during a strike

Sense 4 verb

employ scabs or strike breakers in

Sense 5 noun

a person who is deemed to be despicable or contemptible

only a rotter would do that

Sense 6 verb

take the place of work of someone on strike

Sense 7 noun

one who reveals confidential information in return for money

Sense 8 verb

give (hair) the appearance of being fuller by using a rat

Sense 9 noun

a pad (usually made of hair) worn as part of a woman's coiffure

Sense 10 verb

catch rats, especially with dogs

Sense 11 verb

give away information about somebody

He told on his classmate who had cheated on the exam