English
skyquake
From sky + quake.
Proto-Germanic *skiwô ‘cloud cover, haze’
Proto-Germanic *skiwją ‘cloud; sky’
Old Norse ský ‘cloud; (plural) sky’
Middle English sky ‘sky; cloud’
English sky
Proto-Germanic *kwakōną ‘to shake, quiver, tremble’
Old English cwacian ‘to quake, tremble, chatter’
Middle English quaken ‘to tremble with fear or anger’
English quake
Today it means
noun An unexplained phenomenon that sounds like a thunderclap, cannon storm earthquake volcano or sonic boom coming from the sky, with no observable cause, heard in various countries around the world.
Language periods are conventional ranges, not dates for this word.
Etymograph / skyquake