early 13c., overlien, "lie upon, cover over," from over- + lie (v.2), or from an unrecorded Old English *oferlicgan. In Middle English also "to have sexual intercourse" (c. 1400). "In use from 12th to 16th c.; in 17-18th displaced by overlay; reintroduced in 19th c., chiefly in geological use" [OED] in reference to the relative position of strata. Related: Overlay; overlain.
updated on November 02, 2019