earthling (n.) Look up earthling at Dictionary.com
Old English yrþling "plowman" (see earth + -ling); the sense of "inhabitant of the earth" is from 1590s. Earthman was originally (1860) "a demon who lives in the earth;" science fiction sense of "inhabitant of the planet Earth" first attested 1949 in writing of Robert Heinlein. Earlier in this sense was earthite (1825).