earthist noun 3adjective 1forms 3 noun3 •[in compounds] One who believes the earth has a specific property or history.'Young earthists' will complain I have skimped their case. — 1987 •A proponent of earthism.Enormous amounts of background work had been done, much of it by earthists, who presented well-reasoned proposals to implement some of their agenda. — 1994 •An advocate for people who live on earth, as opposed to those on other planets.He moved forward, determinedly trampling on people's feet. "Make way for an earthist," he called out in a polite but ringing tone. — 1967 adjective1 •Pertaining to earthism.People with earthist sentiments are getting wind into their sails worldwide; they are likely to command enormous political power in coming decades — without, one hopes, evolving into bureaucracies. — 2000 formsearthists · more earthist · most earthist