Antonyms for the word "most unsuspicious" refer to words that indicate something that is full of suspicion or distrust. Words that come to mind include words like doubtful, mistrustful, suspicious, uncertain, worried, and cautious. These words imply a sense of unease and caution when dealing with a particular situation, person, or thing. These antonyms suggest that the subject at hand is not trustworthy, and one must be careful when dealing with it. They can indicate that something is threatening, unsafe, or potentially dangerous. The opposite of "most unsuspicious" is therefore something that arouses caution or distrust, instead of something that is open and unthreatening.