IPA: /ˌʌnəˈkaʊntəbl/
KK: /ʌnəˈkaʊntəbl/
Not responsible for one's actions or decisions; not required to explain or justify them.
The manager was unaccountable for the mistakes made by the team.
Unaccountable → It is formed from "un-" (meaning not) and "accountable" (from Latin "computare", meaning to count or calculate, combined with the suffix "-able", meaning capable of). The word "unaccountable" means not capable of being counted or explained, often referring to something that cannot be justified or explained.
Think of 'not' ('un-') being added to 'capable of being counted or explained' ('accountable') — that's why unaccountable means something that cannot be explained.