Where did the name "flu-flu" come from?

[100%TtId]

I fletched up a bunch of bird arrows and got to thinking what a silly name "flu-flu" is for a bird arrow.

Anyone know the origin of the name?

[caughtandhobble]

I can only guess. I would say when I shoot at a bird, it still flu by, when I shot at another it flu by to, hence flu flu.

OK, I don't know...