Diirkey
Fairy is to fag as Diirkey is to dike. In order to understand this see below for word derivation:

FAIRY/FAG = X/DIKE

F&A CANCEL OUT:

(IRY/G)= X/DIKE

MULTIPLY BOTH SIDE BY DIKE:

(DIKE)(IRY)/G=X

MULTIPLY BOTH SIDE BY G:

(DIKE)(IRY)=GX

WHERE G IS THE GENDER MODULUS AND CAN BE APPROXIMATED AS 1 WHEN CONSIDERING ONLY MALE AND FEMALE (REAL) GENDERS.

EXPANDING:

DIKEIRY=X

RE-ARRANGEMENT

X= DIIKERY
"Is that girl a lesbian?"
"I don't know, but she's such a diirkey."