stick-in-the-mud

[ stik-in-thuh-muhd ]
/ ˈstɪk ɪn ðəˌmʌd /

noun

someone who avoids new activities, ideas, or attitudes; old fogy.

Origin of stick-in-the-mud

First recorded in 1725–35

British Dictionary definitions for stick in the mud

stick-in-the-mud

noun

informal a staid or predictably conservative person who lacks initiative or imagination