The phrase "putting it over" generally means to deceive or trick someone. Some common antonyms for this phrase include honesty, sincerity, and straightforwardness. Instead of putting something over on someone, you can be open and honest with them. Alternately, you can avoid deception altogether and simply tell the truth. Other antonyms for "putting it over" might include being truthful, transparent, forthright, or candid. By avoiding deceptive tactics and communicating clearly and honestly, you can build stronger, more trusting relationships with those around you.