thunderstone

== English == === Etymology === From thunder +‎ stone. === Noun === thunderstone (plural thunderstones) (archaic) A thunderbolt. A stone or fossil thought to be, or be caused by, a thunderbolt striking the earth. A belemnite. === References === “thunderstone”, in Webster’s Revised Unabridged Dictionary, Springfield, Mass.: G. & C. Merriam, 1913, →OCLC.