"fixed quantity of yarn doubled over and over and knotted," early 14c., skaine, from Old French escaigne, escagne (mid-14c., Modern French écagne), a word of uncertain origin. Compare Medieval Latin scagna "a skein," Irish sgainne "a skein, clue."

"ball of thread or yarn," northern English and Scottish relic of Old English cliewen "sphere, ball, skein, ball of thread or yarn," probably from West Germanic *kleuwin (source also of Old Saxon cleuwin, Dutch kluwen), from Proto-Germanic *kliwjo-, perhaps from a PIE *gleu- "gather into a mass, conglomerate," from the source of clay (q.v.). For further sense evolution, see clue (n.).