Ó Somacháin
Ó SOMACHÁIN—I—O Somaghan, O Summaghan, O'Summachan, O'Summahan, Somahan, Sumahean, &c., (Sommers, Summers, Somers, Summerly, Somerville, Summerville, &c.); 'descendant of Somachán' (a soft, innocent person); the name of an old Sligo family who were formerly numerous and respectable in the parish of Ballysummaghan; now generally anglicised Somers.
Alphabetical Index to Irish Surnames