Perhaps: fixed, inflexible; unreasonable.

= inexplicable, adj. 2.

That cannot be explained; inscrutable, unintelligible; (in later use) that cannot be accounted for, unaccountable.

Involving distinctions that are fine or delicate, esp. to such an extent as to be difficult to analyse or describe. Cf. nice, adj. 7b.

Not resolved or explained; left ambiguous or obscure. Obsolete.

Involving distinctions that are fine or delicate, esp. to such an extent as to be difficult to discern or analyse; (also) almost imperceptible…

(un-, prefix1 affix 1.)

In weaker or more general sense: That cannot be understood; inconceivable, unintelligible.

(un-, prefix1 affix 1b.)

Incapable of being unfolded.

That cannot be explained; inexplicable.

(un-, prefix1 affix 1b.)

(un-, prefix1 affix 1b.)

Insoluble, inexplicable; = indissoluble, adj. 5.

That cannot be accounted for or explained; inexplicable. Also absol.

That cannot be accounted for or explained; unaccountable.

Inexplicable.

That cannot be deciphered or made out; indecipherable. transferred.

That cannot be resolved into elements or parts; that cannot be analysed.

Incapable of being deciphered or made out.

(un-, prefix1 affix 1b.)

That cannot be construed.

Incapable of being unravelled; that cannot be disentangled.