Wiktionary
ultradeep
a. Very deep alt. Very deep
Usage examples of "ultradeep".
Too, the British have been trying out a new ultradeep TV drogue, which will go down deeper than a 'nef has been taken so far.
Pollock asserted that the rock formed in an ultradeep oceanic environment where extreme pressure metamorphosed a pre-existing rock, permitting some of the disparate metals to fuse.