Fuddy-duddy
A fuddy-duddy (or fuddy duddy or fuddy-dud) is a person who is fussy while old-fashioned, traditionalist, conformist, or conservative, sometimes almost to the point of eccentricity or geekiness. It is a slang term, mildly derogatory but sometimes affectionate too and can be used to describe someone with a zealous focus on order.
Application
Ambrose Bierce's story Who Drives Oxen Should Himself be Sane, published in 1918, starts out with a use of the phrase and discussion of it as a "unique adjuration". Fuddy-duddy is used to indicate "stuffiness" and "outmoded tastes and manners". The Rolls Royce car manufacturer was referred to as a fuddy-duddy brand in a 2004 Popular Science article. It is also used in the title of juvenile fiction novels including Kay Hoflander's The Chautauqua Kids and the Fuddy Duddy Daddy: A Tale of Pancakes & Baseball,Uncle Fuddy-Duddy Rabbit Tales by Roy Windham and Polly Rushton. and Uncle Fuddy-Duddy Learns to Fly!.
Etymology
Fuddy-duddy is considered a word based on duplication and may have originated as a fused phrase made to form a rhyming jingle. Duddy is similar to Daddy and may have caught on from children's rhyming.