Classical English.  A correspondent [LL] has found this name and its derivative form Sueton in Scottish records:

"Suetonius Cumming was Christened in Duthil With Rothiemurchus, Inverness, Scotland on 12 June 1824. The name appears to be a homage to Julius Suetonius [c.100BC - c.45BC].

"The derivative name, Sueton [q.v.], while rare, does occur in the Grant family lineage, mainly in Morayshire and Inveness-shire, Scotland, in the late 18^th and early 19^th centuries."