Japanese edit

For pronunciation and definitions of ふかかい – see the following entry.
不可解
[adjective] incomprehensible, mysterious, baffling
[adjective] insoluble, insolvable, inexplainable, inexplicable
[noun] incomprehensibility, mysteriousness
[noun] insolubility, inexplicability
(This term, ふかかい, is the hiragana spelling of the above term.)