A vacillator is a person who has difficulty making decisions and often wavers between two choices. Synonyms for vacillator include indecisive person, ditherer, waverer, fence-sitter, hesitator, and equivocator. These terms describe someone who struggles to commit to a choice and may change their mind frequently. Some other related words that may be used as synonyms for vacillator include ambivalent, uncommitted, unsure, and hesitant. If someone is a vacillator, it can be frustrating for those around them who need a definitive answer. It is important for a vacillator to work on making decisions confidently and efficiently to be more productive in their personal and professional lives.