The phrase "give the once over" means to quickly examine or inspect something or someone. Its antonyms would be to ignore, neglect, or overlook. While "give the once over" suggests a thorough look, antonyms like "skim over" or "glance at" imply a casual or superficial inspection. Other antonyms could be to disregard, dismiss, or pass over without consideration. When we use antonyms for "give the once over," we indicate that we are not interested in making an effort to analyze or evaluate something or someone more closely.