I used to know a guy named Fidelis, so I definitely think of it as a male name. It always reminds me of "Adeste Fideles" ("O Come All Ye Faithful"), but I think it's rather nice. .CatherineAnnGenevieve.
"Adeste Fidelis" -- how nice. I had forgotten that reference. Thanks! (One of my favorite Christmas carols, too. I wonder how I could have forgotten it.)