rat

[rat]

noun

1. any of several long-tailed rodents of the family Muridae, of the genus Rattus and related genera, distinguished from the mouse by being larger.

2. any of various mammals similar to or related to the long-tailed rodents of the genus Rattus.

3. Slang.,  a scoundrel.

4. Slang.

   1. a person who abandons or betrays their party or associates, especially in a time of trouble.

   2. an informer.

   3. a scab laborer.

5. Slang.,  a person who frequents a specified place: gym rats.

   a mall rat;

   gym rats.

6. a pad with tapered ends formerly used in women's hairstyles to give the appearance of greater thickness.

interjection

1. Slang.,  rats, (an exclamation of disappointment, disgust, or disbelief.)

verb (used without object)

ratted, ratting 

1. Slang.

   1. to desert one's party or associates, especially in a time of trouble.

   2. to turn informer; squeal.

      He ratted on the gang, and the police arrested them.

   3. to work as a scab.

2. to hunt or catch rats.

verb (used with object)

ratted, ratting 

1. to make (the hair) appear thicker by use of a small pad of material or by teasing.

verb phrase

1. rat out,  to inform on.

   He ratted out his partners in exchange for a lighter sentence.

rat

/ ræt /

noun

1. any of numerous long-tailed murine rodents, esp of the genus Rattus , that are similar to but larger than mice and are now distributed all over the world See also brown rat black rat

2. informal,  a person who deserts his or her friends or associates, esp in time of trouble

3. informal,  a worker who works during a strike; blackleg; scab

4. slang,  an informer; stool pigeon

5. informal,  a despicable person

6. to detect something suspicious

verb

1. informal

   1. to divulge secret information (about); betray the trust (of)

   2. to default (on); abandon

      he ratted on the project at the last minute

2. to hunt and kill rats

Other Word Forms

• ratlike adjective

Word History and Origins

Origin of rat¹

First recorded before 1000; Middle English rat(t)te, Old English ræt; cognate with Dutch rat, German Ratz, Ratte

Word History and Origins

Origin of rat¹

Old English rætt ; related to Old Saxon ratta , Old High German rato

Idioms and Phrases

Idioms

1. smell a rat, to suspect or surmise treachery; have suspicion.

   After noting several discrepancies in his client's story, the attorney began to smell a rat.

More idioms and phrases containing rat

• like a drowned rat
• smell a rat

Example Sentences

Mr Frémond says not only is this unsightly, it attracts foxes and rats and obstructs the pavement.

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Puffins have been seen on the Isle of Muck in County Antrim for the first time in years, after a major scheme to remove invasive brown rats.

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When a rat made its way on to the pitch, Johnson was one of the players who tried to usher it off to the sidelines.

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Riley revealed: "I'm petrified of rats, confined spaces and the dark."

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In animal studies, the treatment successfully healed spinal injuries in rats that mimic osteoporosis-related fractures seen in humans.

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