Etymology A variant pronunciation of That's the boy!, a cry of encouragement, especially to children and pet dogs.
1
Colloquial, Idiomatic Used to show encouragement or approval to a boy, man, or male animal.
Attaboy! That's the way to hit a home run!
[Steve] Bannon responded: “They went for an hour instead of 30 minutes--- showing the entire hour over multiple platforms.” [Jeffrey] Epstein shot back “atta boy”.2025 November 14, Jason Wilson, quoting Jeffrey Epstein, “Jeffrey Epstein advised Steve Bannon during 2018 pro-Trump media campaign”, in The Guardian, →ISSN:
attaboy
noun
Etymology A variant pronunciation of That's the boy!, a cry of encouragement, especially to children and pet dogs.
1
A cry of encouragement; an accolade.
LOS ANGELES, June 29 — Drink in hand, attaboys coming at him from every direction, Tom DeSanto was living the fanboy dream.2007 June 30, David M. Halbfinger, “How a Fan of Comic Books Transformed Himself Into a Hollywood Player”, in New York Times: