Etymology: < Old Norse skál strong feminine, bowl, (plural) (weighing) scales (Swedish skål , Danish skaal : compare skol n.) = Old High German scâla (Middle High German schâle , modern German schale ) < Germanic *skǣlā , ablaut-variant of *skalā , whence Old English scealu shell, hust, drinking cup, weighing scale (see shale n.¹), Old High German scala shell, husk (Middle High German, modern German schale ); the quantity of the vowel is doubtful in Old Saxon skala cup, and in the Old Dutch antecedent of Middle Dutch schale (Dutch schaal ), though it is probable that in Dutch as in German two original forms, skâla cup, scales, and skăla husk, shell, have become phonetically coincident. For the Old English scealu the inflection appears to attest the short vowel in all the senses. The West Germanic *skāla ( < Germanic *skǣlā , skalā ) passed into Old French as eschale , escale cup (medieval Latin scala ‘patera’), also husk (modern French écale ). For the Germanic root *skel- : skal- : skǣl- to separate, divide, compare shale n.¹, shell n., skill n.¹ See also skele n.Between the first quarter of the 13th cent. and the 16th cent. the α forms (containing the vowel a) represent the northern pronunciation, the β forms being midland and southern. In the 16th cent., however, the northern scale seems to have found its way into the London dialect, being used by Palsgrave and later by Spenser and Shakespeare. In the 17th cent. scale is the prevailing literary form, though scole (with other equivalent spellings) occasionally appears down to the middle of the century.

Etymology: aphetic < Old French escale (12th cent.), modern French écale husk, pod, chip of stone < Germanic *skalā (see scale n.¹, shale n.¹). Old French had also escaille (13th cent.), modern French écaille scale of fish, shell of oyster, etc. = Italian scaglia < Romanic (also medieval Latin) scalia , < Germanic *skaljā (see shell n.) from the same root; this is perhaps the source of some of the Middle English spellings.

Etymology: < Italian scala or its source Latin scāla < prehistoric *scanslā (scand- + -tlā ), < scandĕre to climb (see scan v. 7). Compare Provençal escala, Spanish escala, Portuguese escala, Old French eschiele (modern French échelle).