Etymology of “weed”
“plant not valued for use or beauty,” Old English weod, uueod “grass, herb, weed,” from Proto-Germanic *weud- (source also of 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.
I actually kind of like that definition more than a “plant in the wrong place” which is often applied, because it speaks of value, utility and aesthetic.
This comes via Google Etymology: a depiction of mentions over time (not sure how this is measured — via Google Books?)…
Curious that usage peaks around 1950, don’t you think…?