There are several synonyms for the phrase "taken by surprise," which means to be caught off guard or unexpectedly. Some alternatives for this phrase include caught unawares, caught off guard, blindsided, stunned, shocked, amazed, dumbfounded, flabbergasted, and staggered. These synonyms emphasize a sense of shock, disbelief, and suddenness, conveying the feeling of being abruptly and unexpectedly caught off guard. Whether in a personal or professional setting, being taken by surprise can be a disorienting experience, and using these synonyms can help to accurately convey this feeling in writing or conversation.