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.
"to leap, spring upward, jump," 1590s, from French bondir "to rebound, resound, echo," from Old French bondir "to leap, jump, rebound;" originally "make a noise, sound (a horn), beat (a drum)," 13c., ultimately "to echo back," from Vulgar Latin *bombitire "to buzz, hum" (see bomb (n.)), perhaps on model of Old French tentir, from Vulgar Latin *tinnitire.
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<a href="https://www.etymonline.com/word/earth-bound">Etymology of earth-bound by etymonline</a>
Harper, D. (n.d.). Etymology of earth-bound. Online Etymology Dictionary. Retrieved $(datetime), from https://www.etymonline.com/word/earth-bound