FW!Sometimes I pronounce it "Eff Dub."
At one time it meant Future Wife!
Now it stands for Fabulous Wife...
It can morph into almost anything, as the situation warrants:
Funny Woman.
Fashionably Witty.
Freaky Witch (nah!)
Fabulous, Wonderful.
Flamboyant Whistler (wha?)
Et cetera.
It is how she signed off one time on a note to me, early in our 2nd courtship, and the meaning keeps changing and growing. She'll always be my FW!