The definition of a weed is a plant that grows easily but is not intentionally being grown or may even be harmful to other plants around it.(noun)
An example of a weed is kudzu, which kills the trees it grows on.
To weed is to remove plants you don’t want growing from an area where you are growing plants intentionally.(verb)
An example of to weed is to pull up the dandelions from your lawn.
Weed is slang for marijuana.(noun)
An example of weed is someone asking at a party if anyone has any “weed” when they want to smoke marijuana.
See weed in Webster's New World College Dictionary
Origin: ME weede < OE weod, akin to LowG wēd: base only in WGmc
Origin: ME wede < OE wæde, garment, akin to OHG wāt (Ger -wand, in leinwand, linen) < IE base *(a)wē-, to weave > ON authna, fate (in reference to the spinning by the fate goddesses)
See weed in American Heritage Dictionary 4
Origin: Middle English
Origin: , from Old English wēod, herb, grass, weed.
Origin: Middle English wede, garment
Origin: , from Old English wǣd.
Learn more about weed