adj. 25B6; adjective UNACCOUNTABLE, unexplainable, incomprehensible, unfathomable, impenetrable, insoluble; baffling, puzzling, perplexing, mystifying, bewildering; mysterious, strange.
understandable.
INEXPLICABLE
Meaning of INEXPLICABLE in English
Concise Oxford thesaurus English vocabulary. Краткий оксфордский словарь английского языка тезаурус. 2012