Ó Ruadhacháin
Ó RUADHACHÁIN—I—Roughan, Roohan, Rohan, Rowan, (Rogan), &c.; 'descendant of Ruadhachán' (diminutive of ruadh, red); a variant of Ó Ruadhagáin, which see; common in West Ulster and Connacht. Its anglicised forms cannot always be distinguished from those of Ó Robhacháin, which see.
Alphabetical Index to Irish Surnames