Middle English scole, scale bowl, scale of a balance, from Old Norse skāl; akin to Old Norse skel shell — more at shell
Noun (2)
Middle English, from Anglo-French escale, eschale, of Germanic origin; akin to Old English scealu shell, husk — more at shell
Noun (3)
Middle English, from Late Latin scala ladder, staircase, from Latin scalae, plural, stairs, rungs, ladder; akin to Latin scandere to climb — more at scan