The term 'give the green light to' is an idiom that means to authorize or approve something. This phrase can be broken down into four crossword solutions: authorize (9 letters), ALLOW (5 letters), OKAY (4 letters), and LET (3 letters). Authorize means to give permission or power to do something, while ALLOW means to permit or agree to something. OKAY is an informal way of expressing approval, and LET is a verb meaning to permit or ALLOW. All four words can be used to express the same idea of giving permission or approval.