weed (n.) Look up weed at Dictionary.com
"plant not valued for use or beauty," Old English weod, uueod "grass, herb, weed," from Proto-Germanic *weud- (cognates: Old Saxon wiod, East Frisian wiud), of unknown origin. Also applied to trees that grow abundantly. Meaning "tobacco" is from c.1600; that of "marijuana" is from 1920s. The chemical weed-killer is attested by 1885.
weed (v.) Look up weed at Dictionary.com
"to clear the ground of weeds," late Old English weodian "to weed," from the source of weed (n.). Figurative use by c.1400. Related: Weeded; weeding; weeder.