If my deer tag says I can harvest Antlerless deer does that mean I can shoot a doe? Or just a antlerless buck?

Any deer without antlers.

I'm certain the regulations for your state have definitions for everything. What do they say the definition of antlerless is?

If you can't manage to locate such information, I'm certain the governing agency (DNR, Fish and Game, or whatever your state calls it) has a telephone number.

Buck, doe or fawn, doesn't matter, as long as it doesn't have antlers.

Any deer without antlers but be extremely careful with button bucks, You can get a citation from a Game Warden. I am not certain of the requirements on a button buck in your state.

Maybe, antlerless is another term for either sex, Some laws are more specific, you need to dead them and know them for sure.