Here's what we know:
* It's likely a regional expression: This phrase seems to be more prevalent in certain areas, possibly rural or with strong historical ties to specific crafts.
* Possible meanings: Some theories suggest "flitter" could refer to:
* A thin, flat piece of wood or metal: Perhaps a woodworking term for a thin veneer or a piece used in making a specific type of object.
* A pancake or other flat food: This is a less likely interpretation, but the association of flatness with food is common.
* A type of fish: Some sources suggest a connection to a flat fish like a flounder, though this is more speculative.
The bottom line: Without more context or specific regional knowledge, it's hard to definitively say what a "flitter" is in this saying.
If you're curious about the origin of this expression, it's best to ask people in the region where you heard it. They might be able to shed some light on its meaning!