[ at-uh-boi ]
/ ˈæt əˌbɔɪ /

interjection Informal.

(used as an enthusiastic expression of encouragement or approval to a boy, man, or male animal.)

Origin of attaboy

1905–10, Americanism; alleged to be a reduced form of that's a boy or that's the boy Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2020

Example sentences from the Web for attaboy

  • He was censured by his colleagues in the House but given an “Attaboy, Charlie!”

    The Daily Beast 2010 Political Awards|Samuel P. Jacobs|December 21, 2010|DAILY BEAST
  • He did go and support the team, and enhance the glory of Zenith, by yelling "Attaboy!"

    Babbitt|Sinclair Lewis
  • In the ominous silence a cracked voice yelped: "Attaboy Fenton!"

    Vulcan's Workshop|Harl Vincent
  • It will be observed that Mr. Burke has given his attaboy a "t" too many.

    Pieces of Hate|Heywood Broun

British Dictionary definitions for attaboy

/ (ˈætəˌbɔɪ) /

sentence substitute

slang, mainly US an expression of approval or exhortation
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012