unfathomed (adj.)
- able
- abysmal
- abyssal
- bottomless
- cavernous
- colossal
- enigmatic
- enormous
- gaping
- immense
- incalculable
- incognizable
- massive
- mighty
- monstrous
- mysterious
- prodigious
- puzzling
- sealed
- soundless
- strange
- tremendous
- unapparent
- unbeknown
- uncharted
- unclassified
- undisclosed
- undiscoverable
- undiscovered
- unexplained
- unexplored
- unfamiliar
- unfathomable
- unheard
- unheard-of
- unidentified
- unknowable
- unknown
- unperceived
- unplumbed
- unrevealed
- unsounded
- unsuspected
- untouched
- vast
- virgin
- yawning
Full many a gem of purest ray serene
The dark unfathom'd caves of ocean bear;
Full many a flower is born to blush unseen,
And waste its sweetness on the desert air.
