IAYF Share definition Flag Acronym for "I asked you first". Often used in Instant Chat. Pronounced: eye - ay -f Person 1: What's your name? Person 2: What's your name? Person 1: IAYF IAYF by xAnne November 1, 2010 0 0 Get merch Get the IAYF mug. Buy Now — $32.95 See more merch