Hair-raisingly is an evocative term that describes something as disturbing, frightening, or thrilling. There are several synonyms that can be used in its place to convey similar emotions. For example, chillingly can be used to describe something that sends shivers down your spine. Similarly, spine-tingling refers to something that causes a physical response, like goosebumps. Heart-stopping suggests an event that causes sudden shock or fear. Another synonym is pulse-pounding, which refers to the racing of a person's heartbeat due to excitement or fear. Ultimately, there are many words that can replace hair-raisingly, depending on the context and the particular emotion you want to convey.