1. Tom is a bit of an old fuddy-duddy He refuses to get a mobile phone or a computer.
2. My music teacher is pretty cool, but my history teacher is an old fuddy-duddy

Similar to: stuffed shirt. Describing someone as an old fuddy-duddy is usually seen as harmless and humorous, whereas calling someone a stuffed shirt can be rude. The expression can refer to either a woman or a man.