stick in the mud

/ˈstɪk ɪn ðə ˌmʌd/
noun
  1. A person who is old-fashioned, boring, or unwilling to try new activities or ideas.
    • The new manager was seen as a stick-in-the-mud because he refused to update the office software.
    • Don't be a stick-in-the-mud—come join us for karaoke tonight!
    • My uncle is such a stick-in-the-mud; he never wants to go anywhere except his favorite restaurant.
Antonyms
What does "stick in the mud" mean? | whatsthatwordmean | whatsthatwordmean