kōˈtilyən, kəˈ- noun
also co·til·lon “, kȯtēyōⁿ
( -s )
Etymology: French cotillon, literally, petticoat, from Old French, from cote coat — more at coat
1. : a ballroom dance for couples that resembles the quadrille and is possibly based on French peasant dances
2. : an elaborate dance executed under the leadership of one couple at formal balls and marked by the giving of favors and frequent changing of partners : german
3. : a formal ball (as one at which debutantes are presented to society)