The phrase "blow lid off" refers to the act of revealing a secret or exposing something hidden. When looking for antonyms for this phrase, we can consider words that convey the opposite meaning of uncovering or revealing. Some possible antonyms could include words such as conceal, cover-up, hide, mask, or obscure. These words suggest the opposite action of keeping something secret or hidden, rather than revealing it to others. While the phrase "blow lid off" might connote a dramatic and revealing moment, its antonyms remind us of the power of secrecy and concealment.