Approval, agreement, or instruction to begin or proceed.
You can start as soon as you get the go-ahead from the president.
Progressive; exerting leadership.
I work for a very go-ahead company that's always looking for new ideas.
Dashing; energetic.
Being a score which gives the scoring team or player the lead in the game.
The pitcher gave up the go-ahead run in the top of the ninth inning.