mid-15c., abbreviation of master (n.); also see mister. Used from 1814 with a following noun or adjective, to denote "the exemplar or embodiment of that quality," as in Mr. Right "the only man a woman wishes to marry" (1826); Mr. Fix-It "one skilled in setting right difficult situations" (1912); Mr. Big "head of an organization; important man" (1940). The Procter & Gamble advertising character Mr. Clean dates from 1959. The plural Messrs. (1779) is an abbreviation of French messieurs, plural of monsieur, used in English to supply the plural of Mr., which is lacking.

Others are reading

Definitions of Mr. from WordNet

Mr. (n.)
a form of address for a man;
Synonyms: Mister / Mr