"Frighteners" is a word that refers to those who cause fear or alarm to others. There are several synonyms that can be used to describe people who serve this role in different contexts. For example, "terrorists" are individuals who use violence to create fear and panic among a population. "Bullies" are people who intimidate and threaten others in order to gain power or control over them. "Menaces" are those who pose a threat or danger to others, while "intimidators" are individuals who use fear to influence or dominate others. Ultimately, the term "frighteners" can apply to a range of people depending on the situation and their methods of inducing fear.