Webster's Revised Unabridged Dictionary · 1913

Inexplicable

Inexplicable , adjective

[Latin inexplicabilis: compare French inexplicable. See In- not, and Explicable.]

Not explicable; not explainable; incapable of being explained, interpreted, or accounted for; as, an inexplicable mystery.
An inexplicable scratching. — Cowper
Their reason is disturbed; their views become vast and perplexed, to others inexplicable, to themselves uncertain. — Burke