1870, "a rustling," from French (19c.), possibly imitative of the rustling of a dress. Meaning "fussy details" is from 1876.
There was a frou-frou of skirts upon the velvet carpet, and the next moment Iris Vincent's arms were about her.
frou-frou, who stands for her, is not in the least the true type.
Then the frou-frou of light silken draperies passed over the soft carpet.
frou-frou is a creature that can love, can suffer, can repent, can die.
He had not seen Juliette's gesture, but he had heard the frou-frou of her skirts, as she seated herself upon the sofa.
But frou-frou is in no sense the true Femme Galante of her day.
Behind him he heard a slight rustling of branches, and, after that, the sound of quick steps and the frou-frou of a silken skirt.
We can almost hear the frou-frou of their garments in his pictures.
It is shocking only to the most prurient of prudes; and in point of morality is infinitely better than frou-frou.
No people in their right senses could have accepted my "frou-frou" instead of Sarah's.
Frilly dress and adornment; frivolous bedizenment: Is that what you want in a girl, chi-chi, frou-frou, fancy clothes, permanent waves?
[1870+; fr French, imitative of the rustling of silk]