rat
     n 1: any of various long-tailed rodents similar to but larger
          than a mouse
     2: someone who works (or provides workers) during a strike
        [syn: {scab}, {strikebreaker}, {blackleg}]
     3: a person who is deemed to be despicable or contemptible;
        "only a rotter would do that"; "kill the rat"; "throw the
        bum out"; "you cowardly little pukes!"; "the British call
        a contemptible person a `git'" [syn: {rotter}, {dirty dog},
         {skunk}, {stinker}, {stinkpot}, {bum}, {puke}, {crumb}, {lowlife},
         {scum bag}, {so-and-so}, {git}]
     4: one who reveals confidential information in return for money
        [syn: {informer}, {betrayer}, {squealer}, {blabber}]
     5: a pad (usually made of hair) worn as part of a woman's
        coiffure
     v 1: desert one's party or group of friends, for example, for
          one's personal advantage
     2: employ scabs or strike breakers in
     3: take the place of work of someone on strike [syn: {scab}, {blackleg}]
     4: give (hair) the appearance of being fuller by using a rat
     5: catch rats, especially with dogs
     6: give away information about somebody; "He told on his
        classmate who had cheated on the exam" [syn: {denounce}, {tell
        on}, {betray}, {give away}, {grass}, {shit}, {shop}, {snitch},
         {stag}]
     [also: {ratting}, {ratted}]
Source: WordNet® 2.0