1. A worker who removes excess material (such as burrs or seams) from cast metal or other manufactured items.
Usage: chiefly British; industrial/manufacturing context
2. A railway worker responsible for maintaining and repairing railroad tracks and roadbed.
Usage: chiefly British; historical/railway terminology

Examples

• The fettler carefully removed the rough edges from the newly cast metal part.
• In the foundry, fettlers worked to smooth and finish each piece before it left the factory.
• The railway fettler inspected the tracks for damage and wear.
• Fettlers were essential to maintaining the integrity of the rail line.
• She trained as a fettler in the manufacturing plant after leaving school.