Rui /rui/ [1 syll.] as a girls' name is pronounced ROO-ee. It is of Japanese origin, and the meaning of Rui is tears; affection . Kreatif forms: Rorui, Ruima, Ruiro.ariations. Rui is an uncommon first name for women but a somewhat popular last name for both adults and children (#123314 out of 150436, Top 82%).