The Oxford Thesaurus An A-Z Dictionary of Synonyms - go-aheadn.

1) permission, approval, leave, authorization, sanction, Colloq say-so, okay or OK, green light, US the nod: I have the go-ahead to proceed with the project. --adj. 2) ambitious, enterprising, progressive, forward-looking, resourceful: The directors, all under thirty, make it a real go-ahead company.