IPA: /ˌʌndɪˈlɪvəd/
KK: /ʌndɪˈlɪvərd/
Not sent or given to the intended recipient.
The package was marked as undelivered due to an incorrect address.
Undelivered → It is formed from "un-" (meaning not) and "delivered" (from Latin "liberare", meaning to free or set free). The word "undelivered" means not having been set free or sent to the intended recipient.
Think of 'not' ('un-') having been 'set free' or 'sent' ('delivered') — that's why undelivered means something that hasn't reached its destination.