Horripilation is a noun that refers to the erection of hairs on the skin due to cold, fear or excitement.

As you might guess, our word of the day is related to the word horror. Both words emanate from the Latin word horrere (hor AIR ay) which means ‘to tremble or shudder.’ When a person’s hair or skin rises up slightly as a result of being horrified, they’re experiencing horripilation.