Random Notes - Mr. is a short form of "master" a term used for a gentleman in olden days. Later the word " master" became "mister: and the short form remained as "
Mr., Mrs., Ms. and Miss – Full Form and Meaning
Mr and Mrs, Ms, and Miss: Meanings, Abbreviations, and Correct Usage
What does MASTER mean? - MASTER Definitions | Abbreviation Finder
Master Short-Form Video Editing: The Ultimate Guide! — Eightify