1. profound, unfathomed, unplumbed, unsounded

situated at or extending to great depth; too deep to have been sounded or plumbed

Example Sentences:
'the profound depths of the sea'
'the dark unfathomed caves of ocean'
'unplumbed depths of the sea'
'remote and unsounded caverns'

Synonyms

• profound
• unfathomed
• unplumbed

2. silent, unsounded

not made to sound

Example Sentences:
'the silent h' at the beginning of honor''
'in French certain letters are often unsounded'

Synonyms

• silent

Similar Words

• inaudible
• unhearable