Not Much To Go On Here

It is indeed Roman, and there's plenty to go on.

"DOMIT" above the portrait led me to look up Domitian; on Wildwinds, this page illustrating Sear #2644 shows examples of coins much like yours.

The page shows coins both in normal "bottom-inwards" legend, and the unusual "bottom-outwards" style which appears on yours. I assume the two styles are actually attributed differently in the major references, as well as the "horse facing left" and "horse facing right" varieties.

If you've got a coin which you can only read some of the letters on, try using the Wildwinds partial inscription search. Just type in what you can read, and it'll try to find matches in it's database. It doesn't always work, but when it does, it can save an awful lot of head-scratching.