The phrase "smelled rat" can be understood as detecting dishonesty or a hidden agenda in a situation. Antonyms for this phrase would then include "trustworthy," "honest," "transparent," and "open." These words reflect a sense of confidence and reliability, and suggest an environment where deception is not present. Other antonyms for "smelled rat" could include "upfront," "candid," "forthright," and "truthful." Such words are indicative of dealing with individuals or situations where honesty is the norm and there is no need for suspicion or distrust. Using antonyms to "smelled rat" reinforces the importance of transparency, trust, and integrity in human interactions.