What’s the difference between earthly and earthy? Once upon a time, they were synonymous, but now, though there isn’t exactly a world of difference between the two terms, they have distinct meanings.
Earthly is an adjective that refers to life on Earth, as opposed to extraterrestrial or spiritual existence. Earthy, by contrast, though it is superficially similar to earthly in its senses, denotes practicality, simplicity, or roughness, coarseness, or crudeness. Flavor, odor, or texture suggestive of soil, mundane matters and plain styles, and ribald humor are all described as earthy.
Synonyms for earthly include earthbound, mundane (itself derived from the Latin word for world), terrestrial and terrene (both the former, a common word, and the latter, rarely employed, are descended from the Latin term for earth), and worldly; these terms, with the exception of earthbound, all relate to nonspiritual matters rather than extraplanetary ones.
The noun from which both earthly and earthy developed is itself rich in meaning and has inspired numerous idiomatic phrases, including several that suggest the sense of earthly: Someone described as down to earth is realistic and sensible; a person described as being the salt of the earth is solid and reliable, and an earth mother is one with nurturing qualities, suggesting that she is an extension of the world, which provides all that humans need to live.
And if someone says to a friend named Joe, “Earth to Joe, Earth to Joe,” the expression suggests that Joe is an astronaut in orbit and the speaker is an earthbound person sending a radio message to Joe to remind him that he figuratively needs to return to Earth’s surface and come to his senses.