Fathomless
Pronunciation : Fath"om*less
Part of Speech : a.
Definition : 1. Incapable of being fathomed; immeasurable; that can not be sounded. And buckle in a waist most fathomless. Shak.
2. Incomprehensible. The fathomless absurdity. Milton.
Source : Webster's Unabridged Dictionary, 1913