Meaning

noun a variable quantity that cannot be resolved into components

adjective of or relating to a musical scale

adjective of or relating to a directionless magnitude (such as mass or speed etc.) that is completely specified by its magnitude

originBorrowed from Latin scālāris, adjectival form from scāla (“a flight of steps, stairs, staircase, ladder, scale”), for *scadla, from scandere (“to climb”); compare scale. The mathematics sense was coined by Irish mathematician and astronomer William Rowan Hamilton in 1846.

Etymology from Wiktionary, CC BY-SA 3.0