Admou”r = Adoinenu Moirenu veRabbeinu/ Adoinaynee Moyreynee veRabbyeyne. (The Admou”r meCreedmoor uses it because it rhymes – in his case it stands for Addled, Moronic and Rabid!)
Only Baba Sali was ever officially referred to as Admou”r as far as I can remember and that was an official title because he was recognized by Chassidim who are used to referring to Rebbes as Admou”r.
Rav Ovadia Yosef shlit”a is referred to as Mara”n.