- s situated at or extending to great depth; too deep to have been sounded or plumbed
remote and unsounded caverns
- s not made to sound
in French certain letters are often unsounded
- Threefold purpose of the Research will be to chart unsounded depths, to study atmospheric electricity, to find out what makes the North Pole attractive to compass needles.
- When they noticed that many shallow earthquakes came from under it, they searched seismograph records for similar earthquake centers in unsounded parts of the oceans.