"having dignity of nature or appearance, of stately character," c. 1600, from majesty + -ic. Related: Majestical (1570s); majestically. The classically correct formation is majestatic (1650s), but this is now archaic or obsolete.
c. 1300, mageste, "greatness or grandeur of exalted rank or character, imposing loftiness, stateliness, qualities appropriate to rulership," from Old French majeste "grandeur, nobility" (12c.), from Latin maiestatem (nominative maiestas) "greatness, dignity, elevation, honor, excellence," from stem of maior (neuter maius), comparative of magnus "great, large, big" (of size), "abundant" (of quantity), "great, considerable" (of value), "strong, powerful" (of force); of persons, "elder, aged," also, figuratively, "great, mighty, grand, important," from suffixed form of PIE root *meg- "great."
Earliest English use is with reference to God or Christ; as a title of address or dignity to kings and queens (late 14c.), it is from Romance languages and originated in the Roman Empire.
Middle English -ik, -ick, word-forming element making adjectives, "having to do with, having the nature of, being, made of, caused by, similar to," from French -ique and directly from Latin -icus or from cognate Greek -ikos "in the manner of; pertaining to." From PIE adjective suffix *-(i)ko, which also yielded Slavic -isku, adjectival suffix indicating origin, the source of the -sky (Russian -skii) in many surnames. In chemistry, indicating a higher valence than names in -ous (first in benzoic, 1791).
In Middle English and after often spelled -ick, -ike, -ique. Variant forms in -ick (critick, ethick) were common in early Modern English and survived in English dictionaries into early 19c. This spelling was supported by Johnson but opposed by Webster, who prevailed.
<a href="https://www.etymonline.com/word/majestic">Etymology of majestic by etymonline</a>
Harper, D. (n.d.). Etymology of majestic. Online Etymology Dictionary. Retrieved $(datetime), from https://www.etymonline.com/word/majestic