Meaning of the word unaccountable in English

What does unaccountable mean in English? Explore the meaning, pronunciation, and specific usage of this word with Lingoland.

unaccountable

US /ˌʌn.əˈkaʊn.t̬ə.bəl/
UK /ˌʌn.əˈkaʊn.tə.bəl/

Adjective

not able to be explained or understood:

Example:
For some unaccountable reason, he forgot his car keys.