Not explained.

Roget 491: ignorant; nescient; unknowing, unaware, unacquainted, unapprised, unapprized^†, unwitting, unweeting^†, unconscious; witless, weetless^†; a stranger to; unconversant^†.    uninformed, uncultivated, unversed, uninstructed, untaught, uninitiated, untutored, unschooled, misguided, unenlightened; Philistine; behind the age.    shallow, superficial, green, rude, empty, half-learned, illiterate; unread, uninformed, uneducated, unlearned, unlettered, unbookish; empty-headed, dizzy, wooly-headed; pedantic; in the dark; benighted, belated; blinded, blindfolded; hoodwinked; misinformed; au bout de son latin, at the end of his tether, at fault; at sea etc. (uncertain) 475; caught tripping.    unknown, unapprehended, unexplained, unascertained, uninvestigated^†, unexplored, unheard of, not perceived; concealed etc. 528; novel.    ... meer laten zien

Roget 519: unintelligible, unaccountable, undecipherable, undiscoverable, unknowable, unfathomable; incognizable^†, inexplicable, inscrutable; inapprehensible^†, incomprehensible; insolvable^†, insoluble; impenetrable.    illegible, as Greek to one, unexplained, paradoxical; enigmatic, enigmatical, puzzling (secret) 533; indecipherable.    obscure, dark, muddy, clear as mud, seen through a mist, dim, nebulous, shrouded in mystery; opaque, dense; undiscernible etc. (invisible) 447^†; misty etc. (opaque) 426; hidden etc. 528; latent etc. 526.    indefinite, garbled etc. (indistinct) 447; perplexed etc. (confused) 59; undetermined, vague, loose, ambiguous; mysterious; mystic, mystical; acroamatic^†, acroamatical^†; metempirical; transcendental; occult, recondite, abstruse, crabbed.    inconceivable, inconceptible^†; searchless^†; above comprehension, beyond comprehension, past comprehension; beyond one's depth; unconceived.    inexpressible, undefinable, incommunicable.    unpredictable, unforeseeable.    ... meer laten zien

Roget 526: latent; lurking etc. v.; secret etc. 528; occult; implied etc. v.; dormant; abeyant.    unapparent, unknown, unseen etc. 441; in the background; invisible etc. 447; indiscoverable^†, dark; impenetrable etc. (unintelligible) 519; unspied^†, unsuspected.    unsaid, unwritten, unpublished, unbreathed^†, untalked of^†, untold etc. 527, unsung, unexposed, unproclaimed^†, undisclosed etc. 529, unexpressed; not expressed, tacit.    undeveloped, solved, unexplained, untraced^†, undiscovered etc. 480.1, untracked, unexplored, uninvented^†.    indirect, crooked, inferential; by inference, by implication; implicit; constructive; allusive, covert, muffled; steganographic^†; understood, underhand, underground; delitescent^†, concealed etc. 528.    ... meer laten zien

Having the reason or cause not made clear.