A hooker, a floosy woman, used to talk with friends as so the proposed bird doesnt know they are being talked about. After awhile of using the word it becomes shortened to I.B.
Pretty girl with nearly no clothing walks bye and touches you "want a massage" to your friend "she's such an Interesting Bird" or "I.B. back there"
by Adriano Villanobo Guzman January 03, 2009