mis·ter /ˈmɪstə $ -ər/ ●○○ noun n1. → Mister
2 spoken especially American EnglishAmENAME OF A PERSON used to address a man whose name you do not know 先生〔用以称呼不知其名的男子〕 mister• This is no joke, mister, it's for real.• Hand down please, mister Grant.• Let me tell you something, mister.• You don't have any change, do you mister?
From Longman Business Dictionary
MisterMis·ter /ˈmɪstə-ər/ noun the full form of MR