It is an adjective.
It is now considered bad style to use it as a noun. It is used as a noun mainly by those who oppose gay rights.
Note that it is an outdated word in general, and should mainly be used in clinical or scientific contexts.
For the most part, the answer seems to be a no. He has spoken out against bullying in the past, and even specifically about homosexual bullying.
part of speech
The part of speech for this particular word is a noun.
The part of speech for "answer" is a noun.
adverb
what part of speech is beneath
The part of speech for "explicit" is an adjective.
The part of speech for "twirl" is a verb.
The part of speech for "unfamiliar" is an adjective.
The part of speech of "came" is a verb.
The part of speech for "lecturer" is a noun.
The part of speech for "indefinite" is an adjective.