An Anglicized spelling of the Welsh Rhys, this traditional boys' name got a big boost for girls in the early 2000s, thanks to the high-profile Ms. Witherspoon (who was actually born Laura Jeanne Reese, her second middle being her mother's maiden name). This spelling has been on the decline for boys since 2003, possibly for the same reason, but remains a strong, simple choice which might pose fewer spelling and pronunciation issues outside of the UK than the Welsh original.

Mostly feminine, though "Office" star Rainn Wilson gives it a slight masculine twist. You might also use this as a short form of Raines.