1. [syn: brown rat, Norway rat, Rattus norvegicus]
The Collaborative International Dictionary of English v.0.48:
Rat \Rat\ (r[a^]t), n. [AS. r[ae]t; akin to D. rat, OHG. rato,
ratta, G. ratte, ratze, OLG. ratta, LG. & Dan. rotte, Sw.
r[*a]tta, F. rat, Ir. & Gael radan, Armor. raz, of unknown
origin. Cf. Raccoon.]
1. (Zool.) One of several species of small rodents of the
genus Rattus (formerly included in Mus) and allied
genera, of the family Muridae, distinguished from mice
primarily by being larger. They infest houses, stores, and
ships, especially the Norway rat, also called brown rat,
(Rattus norvegicus formerly Mus decumanus), the black
rat (Rattus rattus formerly Mus rattus), and the roof
rat (formerly Mus Alexandrinus, now included in Rattus
rattus). These were introduced into America from the Old
World. The white rat used most commonly in laboratories is
primarily a strain derived from Rattus rattus.
[1913 Webster +PJC]
2. A round and tapering mass of hair, or similar material,
used by women to support the puffs and rolls of their
natural hair. [Local, U.S.]
3. One who deserts his party or associates; hence, in the
trades, one who works for lower wages than those
prescribed by a trades union. [Cant]
Note: "It so chanced that, not long after the accession of
the house of Hanover, some of the brown, that is the
German or Norway, rats, were first brought over to this
country (in some timber as is said); and being much
stronger than the black, or, till then, the common,
rats, they in many places quite extirpated the latter.
The word (both the noun and the verb to rat) was first,
as we have seen, leveled at the converts to the
government of George the First, but has by degrees
obtained a wider meaning, and come to be applied to any
sudden and mercenary change in politics." --Lord Mahon.
Bamboo rat (Zool.), any Indian rodent of the genus
Beaver rat, Coast rat. (Zool.) See under Beaver and
Blind rat (Zool.), the mole rat.
Cotton rat (Zool.), a long-haired rat (Sigmodon
hispidus), native of the Southern United States and
Mexico. It makes its nest of cotton and is often injurious
to the crop.
Ground rat. See Ground Pig, under Ground.
Hedgehog rat. See under Hedgehog.
Kangaroo rat (Zool.), the potoroo.
Norway rat (Zool.), the common brown rat. See Rat.
Pouched rat. (Zool.)
(a) See Pocket Gopher, under Pocket.
(b) Any African rodent of the genus Cricetomys.
Rat Indians (Ethnol.), a tribe of Indians dwelling near
Fort Ukon, Alaska. They belong to the Athabascan stock.
Rat mole. (Zool.) See Mole rat, under Mole.
Rat pit, an inclosed space into which rats are put to be
killed by a dog for sport.
Rat snake (Zool.), a large colubrine snake (Ptyas
mucosus) very common in India and Ceylon. It enters
dwellings, and destroys rats, chickens, etc.
Spiny rat (Zool.), any South American rodent of the genus
To smell a rat. See under Smell.
Wood rat (Zool.), any American rat of the genus Neotoma,
especially Neotoma Floridana, common in the Southern
United States. Its feet and belly are white.
WordNet (r) 3.0 (2006):
n 1: common domestic rat; serious pest worldwide [syn: brown
rat, Norway rat, Rattus norvegicus]