The phrase "tight corner" generally refers to a difficult situation or predicament where someone feels trapped and unable to escape easily. The antonyms or opposites of this phrase could be "wide open", "freedom", "easy street", or "a piece of cake". In these contexts, the meaning is that the person is in a comfortable, spacious, or effortless situation. Other antonyms might include "safe zone", "comfort zone", or "successful position." Overall, the opposite of a tight corner refers to a situation where one feels confident, secure, and in control.