This sign can be used to mean "SPELL."
If I want to sign FINGERSPELLING, I use a double movement: I use a "rolling wiggle" movement of my hand as I move it two inches to the side, then I move it quickly back and repeat the "rolling wiggle" movement.
If I want someone to "spell" their name to me I do the movement just once and then sign "NAME."
SPELL or FINGERSPELL:
SPELL: Variation 2:
There is another way to sign fingerspell which looks like you are throwing a piece of paper. It uses a quick double movement.
I use this sign for sentences like: "I spelled to them." "He spelled to me." This sign is "directional," it involves "noun/verb" agreement. That means if you do it like in the picture it means SPELL in general or "I SPELLED it to YOU." But you can modify the sign by aiming it at a third person or even at yourself. If I aim it at myself it could mean the person I am talking about spelled something to me.
Note: if you use just a single movement with this variation it can mean SEND.