eeriest
/ˈɪəriːɪst/Definitions
1. adjective
most strange, frightening, or unusual; giving the strongest impression of something strange or frightening
“The eeriest part of the haunted house was the creaking stairs.”
2. superlative adjective
more than the superlative degree of eerie; more strange, frightening, or unusual than anything else
“The city at night was the eeriest place I’ve ever been.”