O’Day (?-d??), Anita Originally Anita Belle Colton. 1919-2006. American jazz singer. Noted for her scat singing, she rose to fame during the Big Band era of the 1940s.American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.