rat

rat · noun, verb¹

1. Proto-Indo-European · derived from*Hreh₃d-“to gnaw, scrape, scratch”
2. Proto-Germanic · inherited from*rattaz
3. Proto-West Germanic · inherited from*ratt
4. Old English · inherited fromræt
5. Middle English · inherited fromraat
6. English todayrat

From Middle English raat, rat, ratt, ratte, rotte, from Old English ræt, rætt, from Proto-West Germanic *ratt, from Proto-Germanic *rattaz, *rattō (“rat”), of uncertain origin, possibly from Proto-Indo-European *Hreh₃d- (“to gnaw, scrape, scratch”). 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. Cognates Cognate with North Frisian root (“rat”), Saterland Frisian Rotte (“rat”), West Frisian rôt (“rat”), Dutch rat, rot (“rat”), German Ratte (“rat”), Luxembourgish Rat (“rat”), Vilamovian rot, rott (“rat”), Yiddish ראַץ (rats, “rat”), Danish and Norwegian Bokmål rotte (“rat”), Faroese and Icelandic rotta (“rat”), Norwegian Nynorsk rotta, rotte, røtte (“rat”), Swedish råtta (“rat”), Latin rattus, ratus (“rat”) (whence Asturian ratu (“mouse”), Catalan rata (“rat”), French rat (“rat”), Italian ratto (“rat”), Portuguese rato (“rat”), Spanish rata (“rat”), rato (“male rat”)); also Latin rōdō (“to bite, gnaw, nibble; to backbite, disparage, slander”), Sanskrit रदति (radati, “to scrape, scratch; to cut path, pave; to lead river into a channel; to bestow, convey”). Some of the Germanic cognates show considerable consonant variation, e.g. Middle Low German ratte, radde; Middle High German rate, ratte, ratze. The irregularity may be symptomatic of a late dispersal of the word, although Kroonen accounts for it with a Proto-Germanic stem *raþō nom., *ruttaz gen., showing both ablaut and a Kluge's law alternation, with the variation arising from varying remodellings in the descendants. Kroonen states that this requires a Proto-Indo-European etymon in final *t and is incompatible with the usual derivation from Proto-Indo-European *Hreh₃d- (“to scrape, scratch, gnaw”).

rat · noun, verb²

1. Middle English · inherited fromratten
2. English todayrat

From Middle English ratten, further etymology unknown. Compare Middle Low German retten (“to tear, tear up”), Middle High German ratzen (“to scratch; rasp; tear”). Could be related to write. See also rit.

rat · verb³

From remote-access Trojan.

Words from the same roots

First known use, by meaning

• from 19th c. To hunt or kill rats.
• from 19th c. To betray a political party, cause or principle; to betray someone, to desert a person or thing.
• from 19th c. To work as a scab, going against trade union policies.
• from 20th c. To backcomb (hair).
• from 20th c. To inform on someone; to betray someone to the police or authorities.