- a fuddy-duddy.
Origin of fud
First recorded in 1910–15; back formation from fuddy-duddy
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
"backside, buttocks," 1785, a Scottish and Northern dialect word of unknown origin, perhaps from Scandinavian.
Online Etymology Dictionary, © 2010 Douglas Harper