Definitions

1. adjective

causing an unpleasant, eerie, or spine-tingling feeling; frightening or unsettling.

“The creepiest part of the movie was when the main character was alone in the dark house.”

2. superlative form of creepy

more creepy than creepy; most frightening or unsettling.

“The creepiest haunted house in town was said to be located at the old mansion on the hill.”