- a temporary fashion, notion, manner of conduct, etc., especially one followed enthusiastically by a group.
- an intense but short-lived fashion; craze
- a personal idiosyncrasy or whim
- biochem flavin adenine dinucleotide: an ester of riboflavin with ADP that acts as the prosthetic group for many flavoproteinsSee also FMN
1834, “hobby, pet project;” 1881 as “fashion, craze,” perhaps shortened from fiddle-faddle. Or perhaps from French fadaise “trifle, nonsense,” ultimately from Latin fatuus “stupid.”
- flavin adenine dinucleotide