IPA: /ˌʌnəˈveɪləbəl/
KK: /ʌnəˈveɪləbəl/
Not able to be accessed or obtained; not present or ready for use.
The product is currently unavailable due to high demand.
Unavailable → It is formed from "un-" (meaning not) and "available" (from Latin "valere", meaning to be strong or to be worth). The word "unavailable" means not able to be accessed or not present.
Think of 'not' ('un-') being combined with 'worth' or 'accessible' ('available') — that's why unavailable means something that cannot be accessed.