"Give once over" is a colloquial phrase that means to quickly inspect or examine something. Antonyms for this phrase could include "ignore," "neglect," or "overlook." To ignore something means to refuse to acknowledge it, while neglecting something involves failing to take proper care of it. Overlooking something, on the other hand, means to miss or fail to notice it. Other antonyms for "give once over" could include "meticulously examine," "thoroughly scrutinize," or "carefully assess." These antonyms emphasize the importance of paying close attention to detail and taking the time to thoroughly evaluate or inspect something.