fettler

noun5

1. •
   A person who maintains railway lines.

   • Sometimes the engine stopped for water, or to drop stores at fettlers' camps, or to accumulate the steam to take it up a heavy grade. — 1938
2. •
   Someone whose job is to sand and grind small imperfections from metal and ceramic castings.
3. •
   Someone who fiddles or tinkers with things.
4. •
   (UK, slang) A friend or mate.

   • How's tha' doing fettler?
5. •
   (historical) An ostler; one who looks after the horses in a mine.