early 14c., isykle, from is "ice" + ikel "icicle," from Old English gicel "icicle, ice" (rel. to cylegicel "cold ice"), from Proto-Germanic *jekilaz (cognates: Old Norse jaki "piece of ice," diminutive jökull "icicle, ice, glacier;" Old High German ihilla "icicle"), from PIE *yeg- "ice." Dialectal ickle "icicle" survived into 20c.