Hi
Lorelle,
I haven't seen Riise used as a first name, but it is a common surname in Norway. I don't know anything about its meaning and origin, but as it doesn't look very Norwegian (there's no double-i in the Norwegian language), there might be a connection to the Finnish first name Riisa (male) which is a Finnish pet form for
Grigori (Russian form of Greek
Gregorios).
Regards,
Satu