rat

Meanings

1. 1
   noun

   A medium-sized rodent belonging to the genus Rattus.

   Similar studies of rats have employed four different intracranial resorbable, slow sustained release systems—surgical foam, a thermal gel depot, a microcapsule or biodegradable polymer beads.

2. 2
   noun

   A person who is known for betrayal.

   Near-synonyms: rouge, scoundrel, snake; see also Thesaurus:villain

3. 3
   noun

   A person who routinely spends time at a particular location.

   Our teenager has become a mall rat.

4. 4
   noun

   Vagina, vulva.

   Get your rat out.

5. 5
   noun

   Ellipsis of muskrat.

   The price of rats began to rise and soon after the marsh froze over, spearing rats began, which was done with a one tine three-eighths inch steel rod, with a wooden handle […]

6. 6
   verb

   To backcomb (hair).

   In 1962, the higher a girl's hair was ratted the more available she was, it was simply understood.

7. 7
   verb

   To inform on someone; to betray someone to the police or authorities.

   He ratted on his coworker.

8. 8
   verb

   To scratch or score.

   He ratted a vertical line on his face with a pocket knife.

Etymology

From Middle English ratte, rat, rotte, from Old English rætt, from Proto-West Germanic *ratt, from Proto-Germanic *rattaz, *rattō (compare West Frisian rôt, Dutch rat), of uncertain origin, possibly from Proto-Indo-European *Hreh₃d- (“to scrape, scratch, gnaw”). However, the rat may have been unknown in Northern Europe in antiquity, and the Proto-Germanic word may have referred to a different animal; see *rattaz for more. Attestation of this family of words begins in the 12th century. Some of the Germanic cognates show considerable consonant variation, e.g. Middle Low German ratte, radde; Midd…