An Etymological Dictionary of Astronomy and Astrophysics

(v.tr.) To change or make different.
(v.intr.) To change or become different.

Etymology (EN): M.E. alteren, from O.Fr. altérer, from M.L. alterre, from L. alter “other,” from PIE *al- “beyond” + comp. suffix -ter.

Etymology (PE): Degargun kardan, degargunidan, from degargun, from degar, → change, + -gun “manner, fashion,” → elliptical, + kardan, -idan, → -ize.