Earthy is from Middle English erthy, from earth + -y. The figurative sense of 'coarse, unrefined' developed from the literal sense of resembling soil. The ancestry passes through Old English eorþe and Proto-Germanic *erþō. The suffix -y forms an adjective meaning characterized by the base, so the English form is shaped by recognizable word formation as well as by its inherited or borrowed base. In present use as an adjective, it means "resembling soil; plainly natural or coarsely direct", keeping the historical formation close to the word's ordinary semantic work. The figurative development named in the history lets the word move from a concrete base into a broader descriptive use. Related words include earth, earthly, and earthen; derived forms include earthiness and earthily.