1To provide a new ground or basis for painting, etching, etc.; especially to provide (a plate) with a new ground for etching.
2To put back on a firm basis or grounding. Chiefly with in.
3To reimbue (a person) with a sense of belonging or perspective; to reimpart mental stability or emotional balance to. Chiefly reflexive.
Mid 19th century; earliest use found in John Constable (1776–1837), landscape painter and draughtsman. From re- + ground.