noun
Literally a floating aquatic plant without roots; used metaphorically for rootlessness.
池の水面に根無し草が浮かんでいる。
Duckweed is floating on the surface of the pond.
noun
rootless person; wanderer
Figurative use for a person without a fixed home, job, or social ties; often carries a nuance of instability or drifting.
彼は根無し草のような生活を送っている。
He leads a rootless, drifting life.