When a person is so far in the closet about being gay that they don't even realize it themselves. As though they are living in an alternate universe.
Also see Narnian
So Scott has been dating Sarah for 4 years now and they have only had sex twice and he only seems to only get turned on around other guys? Wow, he's Narnia Deep.
The actor/actress in a play or musical that is obviously the best, but is always getting the crappy roles in plays/musicals do to obvious favoritism of the director.
Boniface: SO, Xylem, what part are you in the play?
Xylem: Oh, I am the tree, but that is OK. Every one tells I'm the Narnia Dwarf, so I'm cool.