surregulus
Could not find subregulo in Logeion dictionaries.
subregulo Noun: masculine ablative singular, Noun: masculine dative singular of surregulus
sur-rēgŭlus (subr-), i, m.,
- a petty prince, a feudatory vassal, Amm.17, 12, 21; Sulp.Sev.Hist. Sacr. 2, 10, 1.