late 14c., from lime (n.1) + stone (n.). So called because it yields lime when burnt. Another name for it, mostly in American English, is limerock.
Entries linking to limestone
lime n.1
"chalky, sticky mineral used in making mortar," from Old English lim "sticky substance, birdlime;" also "mortar, cement, gluten," from Proto-Germanic *leimaz (source also of Old Saxon, Old Norse, Danish lim, Dutch lijm, German Leim "birdlime"), from PIE root *(s)lei- "slime, slimy, sticky" (source also of Latin limus "slime, mud, mire," linere "to smear;" see slime (n.)).
Bird-lime is prepared from the bark of the holly, it was spread on twigs and used for catching small birds. The lime used in building, etc. is made by putting limestone or shells in a red heat, which burns off the carbonic acid and leaves a brittle white solid which dissolves easily in water. Hence lime-kiln (late 13c.), lime-burner (early 14c.). As a verb, c. 1200, from the noun.
stone n.
Old English stan, used of common rocks, precious gems, concretions in the body, memorial stones, from Proto-Germanic *stainaz (source also of Old Norse steinn, Danish steen, Old Saxon sten, Old Frisian sten, Dutch steen, Old High German stein, German Stein, Gothic stains), from PIE *stoi-no-, suffixed form of root *stai- "stone," also "to thicken, stiffen" (source also of Sanskrit styayate "curdles, becomes hard;" Avestan stay- "heap;" Greek stear "fat, tallow," stia, stion "pebble;" Old Church Slavonic stena, Russian stiena "wall").
Sense of "testicle" is from late Old English. The British measure of weight (usually equal to 14 pounds) is from late 14c., originally a specific stone. Stone-fruit, one with a pit, is from 1520s. Stone's throw for "a short distance" is attested from 1580s. Stone Age is from 1864. To kill two birds with one stone is first attested 1650s. To leave no stone unturned is from 1540s.