noun:someone who has old-fashioned ideas or who does not like trying new or exciting things
noun:one who is slow, old-fashioned, or unprogressive
Examples
He's just an old 'stick-in-the-mud'.
Movie quotes
(..) Who else around here could run a projector? Nobody. lt takes an imbecile like me. And l never had any luck. So! Want to be a stick-in-the-mud like me? How about it? Attaboy, Toto. l only tell you for your own good. Cooped up here. Suffocate in summer, (..)