roots — a part of the body of a plant that develops, typically, from the radicle and grows downward into the soil, anchoring the plant and absorbing nutriment and moisture.
grassroots — the common or ordinary people, especially as contrasted with the leadership or elite of a political party, social organization, etc.; the rank and file.
grass roots — the common or ordinary people, especially as contrasted with the leadership or elite of a political party, social organization, etc.; the rank and file.