Anything that seems a little off or out of place, or a person not quite right in the head.
That cole slaw seems a little fishtaygle as if it was made 2 weeks ago.
Steer clear of Cleatus, he's been acting real fishtaygle since he ran out of meth.
n. An illegal car manuever where the driver of a 4WD vehicle causes the rear tires to swing back and forth leaving fish tail-shaped tracks, often to create a dust cloud for anyone who might be following.