What is the meaning of Fettle?

A state of physical condition; kilter or trim.

One's mental state; spirits.

Sand used to line a furnace.

A seam line left by the meeting of mould pieces.

The act of fettling.

A person's mood or state, often assuming the worst.

To sort out, to fix, to mend, to repair.

To make preparations; to put things in order; to do trifling business.

To line the hearth of a furnace with sand prior to pouring molten metal.

To be upset or in a bad mood.

To remove (as by sanding) the seam lines left by the meeting of two molds.

To machine away seam lines or more generally to make small adjustments to a component or machine to improve its fit or operation.

To prepare.

Source: wiktionary.org