The term "weed" has no botanical significance because a plant that is a weed in one context is not a weed when growing in a situation where it is wanted. Methods include hand cultivation with hoes, powered cultivation with cultivators, smothering with mulch or soil solarization.
See also: Weed (disambiguation), Weed, California, Weed control, Jeremiah Weed, Skunk weed, and Weed (manga).