From Longman Dictionary of Contemporary Englishgive (somebody) the go-ahead/get the go-aheadgive (somebody) the go-ahead/get the go-aheadLET/ALLOWto give or be given permission to start doing something The company has been given the go-ahead to build a new supermarket. → go-ahead
Examples from the Corpus
give (somebody) the go-ahead/get the go-ahead• The state utilities commission gave the go-ahead for the water company to raise rates. 