Acroceraunian

Latin Acroceraunius, from Ancient Greek ἄκρος (ákros, “high, heights”) + κεραυνός (keraunós, “thunderbolt”).

Acroceraunian (not comparable)

1. (archaic) Of or relating to the Ceraunian Mountains
   • 1854, Herman Melville, The Lightning-Rod Man:

     What grand irregular thunder, thought I, standing on my hearthstone among the Acroceraunian hills, as the scattered bolts boomed overhead and crashed down among the valleys, every bolt followed by zigzag irradiations, and swift slants of sharp rain, which audibly rang, like a charge of spear-points, on my low shingled roof.

• “Acroceraunian”, in Webster’s Revised Unabridged Dictionary, Springfield, Mass.: G. & C. Merriam, 1913, →OCLC.