Attaboy (interjection)

An exclamation of praise or encouragement, especially addressed to a man or boy.

Origin:

This phrase is likely a shortening of the phrase 'that's the boy' which was used to express approval or praise. the phrase has been used in the us since the early 20th century.

Examples:

1. Attaboy, you did a great job on that presentation.
2. Keep up the good work, attaboy!
3. You hit the home run, attaboy!
4. Attaboy, you passed your exams!
5. You learned how to play guitar, attaboy!