The only free and comprehensive online etymological dictionary of the Spanish language
majestad f. (Noun) "majesty"
From Late Latin maiestatem, accusative maiestas "authority." Derived from maior "greater" (see mayor) and -tas, a noun-forming suffix (see -dad).
Indo-European
Romance
Portuguese majestade, French majesté
Real Academia Española. Diccionario de la lengua española. Online. 23rd ed. Madrid: Espasa Calpa. 2014. http://www.rae.es/.
Sihler, A. New Comparative Grammar of Greek and Latin. Oxford University Press. 2008.