I. ˈrüdərəl adjective
Etymology: New Latin ruderalis, from Latin rudera + -alis -al
of a plant : growing in rubbish or in a waste or disturbed place
II. noun
( -s )
: a weedy and commonly introduced plant growing where the native vegetational cover has been interrupted ; especially : a weed other than a grass growing where the vegetation has been disturbed by man (as in old fields or along roadsides)