Many Hispanics have such names ~ with this one I'm guessing "se" has something to do with the maneuvering of mounted knights in battle.
"Sa", for example, means "flag", and that always refers to the gentleman who carried the flag on which mounted knights lined up, and a "se" would be a first derivative of that ~ maybe "move horse forward guy"? "na" is pretty clearly Cornish ~ which, although no longer spoken, has a cognate language in Breton and Northern Welsh. The "root" sound here is "n", so maybe "from"?
Outside of the "big 5" names, lots of Mexicans can be found wandering about with these names ~ which are a total mystery to them since they are usually "sentences" and are cast in what is pretty obviously a "foreign language".
The oddball fun fact of the day.
; )