1835, from Mod.L.
rodentia, the order name, from L.
rodentem (nom.
rodens), prp. of
rodere "to gnaw, eat away," from PIE base
*red- "to scrape, scratch, gnaw" (cf. Skt.
radati "scrapes, gnaws,"
radanah "tooth;" L.
radere "to scrape;" Welsh
rhathu "scrape, polish"). Uncertain connection to O.E.
rætt (see
rat).