IPA: /ˈhɔːntər/
KK: /ˈhɔntər/
A person or spirit that frequently visits or appears in a place, often in a ghostly or eerie manner.
The old house was said to be the home of a haunter that scared away anyone who tried to enter.
Haunter is formed from "haunt" (from Old French *hanter*, meaning to frequent or visit) and "-er" (meaning a person who). A haunter is a person or entity that frequents or visits a place, often in a ghostly or eerie manner.
Think of someone who 'frequents' ('haunt') a place, and the '-er' indicates that this person is doing the haunting.