ATTAGIRL

(slang) an exclamation of approval or encouragement. (A corruption of "that's the girl," this expression is also seen as "that's a girl" and "thatagirl.") —SHSBC Binder 12 Approved Glossary

(slang) an exclamation of approval or encouragement. (A corruption of "that's the girl," this expression is also seen as "that's a girl" and "thatagirl.") (slang) short for that's the girl, an exclamation expressive of encouragement.a variation of that's the girl. (slang) an exclamation of approval or encouragement. (A corruption of, "that's the girl," this expression is also seen as "that's a girl" and "thatagirl.") Yeah, sit forward. Way up. Attagirl. - TV Demo Prepchecking, Part 1 (2 May 62)