Dino

Also Galician: http://www.ige.eu/igebdt/esq.jsp?idioma=gl&ruta=onomast/nomes.jsp
https://gl.wikipedia.org/wiki/Lista_de_nomes_masculinos_en_galego#N

I know a guy called Dean who we call Dino. I think it's quite a common nickname for Dean.

Also a boys name in Croatia. [noted -ed]

I know a Croatian boy named Dino. It's not a nickname, it's his actual name.