An Etymological Dictionary of Astronomy and Astrophysics

Quantity; measure; the sum total of two or more quantities or sums.

Etymology (EN): From M.E. amounten “to ascend,” from O.Fr. amonter, from amont “upward,” from L. ad montem “to the hill,”
from ad “to” + mons, mont “hill,” → mountain.

Etymology (PE): Masâk, from Mid.Pers. masâk “size, amount, magnitude,” from mas “great, large,” Av. masan “greatness, importance,” from mas-; maz- “long, large; great”; cp. Skt. maha “great, mighty” (Mod.Pers. meh “great, large”),
Gk. megas “great, large” L. magnus “great,” PIE *meg- “great”.