rot (v.) Look up rot at Dictionary.com
Old English rotian "to decay, putrefy," from Proto-Germanic *rutjan (cognates: Old Saxon roton, Old Norse rotna, Old Frisian rotia, Middle Dutch roten, Dutch rotten, Old High German rozzen "to rot," German rößen "to steep flax"), from stem *rut-. Related: Rotted; rotting.
rot (n.) Look up rot at Dictionary.com
early 14c., from rot (v.) or of Scandinavian origin (compare Icelandic rot, Swedish röta, Danish røde "decay, putrefaction"), from the root of the verb. Slang noun sense of "rubbish, trash" is from 1848.