Merriam-Webster Collegiate Dictionary - butterfly

 I. noun  Usage: often attributive  Date: before 12th century  1. any of numerous slender-bodied diurnal lepidopteran insects including one superfamily (Papilionoidea) with broad often brightly colored wings and usually another superfamily comprising the skippers  2. something that resembles or suggests a ~; especially a person chiefly occupied with the pursuit of pleasure  3. a swimming stroke executed in a prone position by moving both arms in a circular motion while kicking both legs up and down  4. plural a feeling of hollowness or queasiness caused especially by emotional or nervous tension or anxious anticipation  5. a defensive move by a goalie in ice hockey executed by dropping to the knees while spreading the lower legs outward  II. transitive verb  (-flied; -flying)  Date: 1954 to split almost entirely and spread apart a butterflied steak butterflied shrimp