"old-fashioned person," 1871, American English, of uncertain origin.
: There were a few fuddy-duddy requests for documentation
An old-fashioned, esp a meticulous, person; an outdated conservative: To this little squab, I evidently rated as a fuddy-duddy (1900+)
An old person, esp a man who clings to old-fashioned ways
[first form 1790+, second 1899+; of fuddy-duddy, origin unknown]