The antonyms for the phrase "gave go ahead" suggest a lack of permission or approval. Some possible antonyms include rejected, denied, disapproved, prohibited, forbid, vetoed, or opposed. These words convey the sense of negation or refusal, indicating that an action or decision was not authorized or deemed acceptable. Alternatively, synonyms for "gave go ahead" include authorized, approved, endorsed, sanctioned, permitted, or allowed. These terms indicate that something has been given consent or clearance to proceed, and convey a sense of affirmation or agreement. Choosing the right words to describe permission or denial can have a significant impact on how a situation is perceived, so it is important to choose words carefully.