Where does “méijor” come from?

méijor (Spanish) comes from English Major, from Middle English major, from Latin māior, from Latin magnus, from Proto-Indo-European meǵh₂- — big, great; great; big, stour, great.

Ancestry of “méijor”, step by step

Step	Language	Word	Meaning
1	English	Major	Title for an army officer with the rank of major
2	Middle English	major	—
3	Latin	māior	ancestors, forefathers; advanced in years, the aged; the elders
4	Latin	magnus	large, big; great; important
5	Proto-Indo-European	meǵh₂-	big, great; great; big, stour, great

Every word from Proto-Indo-European meǵh₂- →Every word from Latin magnus →Every word from Latin māior →