weeds and grass that look like rice seedlings but produce no grain; specifically the weeds [[稂|稂|lang2]] and [[莠|莠|you3]]

useless; good-for-nothing; worthless; originally referring to a field without weeds, this idiom now describes someone who has failed to grow into a capable person or lacks any promise

(proverb) to be good-for-nothing or useless; used to describe a person who has failed to amount to anything or who is unable to make a living