Rat, v. i. [imp. & p. p. Ratted; p. pr. & vb. n. Ratting.]
  1. In English politics, to desert one's party from interested motives; to forsake one's associates for one's own advantage; in the trades, to work for less wages, or on other conditions, than those established by a trades union.
     Coleridge . . . incurred the reproach of having ratted, solely by his inability to follow the friends of his early days.   --De Quincey.
  2. To catch or kill rats.
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  Rat·ting n.
  1. The conduct or practices of one who rats.  See Rat, v. i., 1.
  2. The low sport of setting a dog upon rats confined in a pit to see how many he will kill in a given time.
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  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]
  ratting
       n : to furnish incriminating evidence to an officer of the law
           (usually in return for favors) [syn: informing]