An abbreviation for A butterfly which can be either call or put whose strikes are not equidistant. In a regular butterfly there is equal distance from the long strike (wing) to the short strikes (body) and from the body to the other wing. Think of al butterflies as simply two verticals, one long and one short. The broken wing butterfly simply has the short vertical being wider than the long vertical. In exchange for some directional risk, the spread is opened for a lower price, often even a credit.