IPA: //ʌnˈlɪstɪd//
KK: /ʌnˈlɪstɪd/
Not included on a list or directory, such as a telephone book or stock exchange.
The unlisted phone number made it difficult to reach him.
Unlisted → It is formed from "un-" (meaning not) and "listed" (from the verb "list", which comes from Old English "listian", meaning to make a list or to enumerate). The word "unlisted" means not included in a list or not enumerated.
Think of 'not' ('un-') being added to 'listed', which means something is not included in a list.