"to commit (a corpse) to earth," late 14c., from earth (n.). Related: Earthed; earthing.

Old English eorþe "ground, soil, dirt, dry land; country, district," also used (along with middangeard) for "the (material) world, the abode of man" (as opposed to the heavens or the underworld), from Proto-Germanic *ertho (source also of Old Frisian erthe "earth," Old Saxon ertha, Old Norse jörð, Middle Dutch eerde, Dutch aarde, Old High German erda, German Erde, Gothic airþa), perhaps from an extended form of PIE root *er- (2) "earth, ground."

The earth considered as a planet was so called from c. 1400. Use in old chemistry is from 1728. Earth-mover "large digging machine" is from 1940.

c. 1600, "firmly fixed in or on the earth," from earth (n.) + bound (adj.). Figurative sense "bound by earthly ties or interests" is from 1869.

"the earth regarded as placed midway between heaven and hell or the abode of the gods and the underworld," late 13c., from middle (adj.) + earth. Altered from earlier middel-erd (late 12c.), midden-erd, itself an alteration (by association with Middle English eard "dwelling") of Old English middangeard (see Midgard).

1870, folkloric spirit of the earth, conceived as sensual, maternal; often a translation of German erdmutter. Earth-goddess is from 1837.

late 14c., "containing or resembling the substance earth," from earth (n.) + -y (2). Of tastes, smells, etc., from 1550s. Figurative sense of "coarse, unrefined" is from 1590s. Related: Earthiness.

"to dig up," mid-15c., from un- (2) "opposite of" + earth (v.) "bury (a corpse) in the ground" (c. 1400, from earth (n.)). Related: Unearthed; unearthing.

also earth-light, "sunlight reflected from Earth's surface and clouds," especially as illuminating the otherwise dark part of the moon, 1810, from earth (n.) + light (n.). Earthshine in same sense is from 1814.

also earth-man, 1860, "a spirit of nature; a demon who lives below the ground," from earth (n.) + man (n.). Science fiction sense of "inhabitant of the planet Earth" first attested 1949 in writing of Robert Heinlein.

as an annual ecological awareness event on April 22, from 1970; the idea for it and the name date from 1969.