(n) Condition. (v) Trim or clean the rough edges of (a metal casting or a piece of pottery) before firing: To repair something.
A word I’ve not heard in years but one which was regularly used by my granddad.
“Despite falling from her horse earlier in the day Elizabeth was in fine fettle at dinner.”
“It’s no problem, I’ll just fettle this back into place and it will be as good as new.”