Emily Dickinson Lexicon

RAT, n. [Sax. ræt; D. rat; G. ratze; Fr. rat; Arm. raz; Sp. rato; Port. id. a rat, and ratos, sharp stones in the sea that wear cables; probably named from gnawing, and from the root of L. rodo.]

The popular name of several species of the genus Mus, which are rodent mammals, or small quadrupeds that infest houses, stores and ships; a troublesome race of animals. To smell a rat, to be suspicious, to be on the watch from suspicion; as a cat by the scent or noise of a rat.