It may be my own more personal take on the term, but, as far as I'm concerned a 'weed' is simply any plant that is in a place you don't want it to be. What otherwise would be a part of a glorious Bermuda lawn, if in the flower bed, gets yanked (is Bermuda grass normally considered a weed? I consider it one if it's in with my Irises!). What otherwise would be a prize winning rose bush, in the middle of a cornfield, could be a weed, too.

Over the years many of the weeds I'd pull from flower beds were things like tiny trees starting to grow or the starts of other ornamental plants.As I said, this could just be my own interpretation, I'm wrong, and scientifically it's more focused than this, but I'm sticking with my definition.
