1. Situated at or extending to great depth; too deep to have been sounded or plumbed
   "remote and unsounded caverns"
   - profound, unfathomed, unplumbed 
2. Not made to sound
   "in French certain letters are often unsounded"
   - silent

See also: deep, inaudible, unhearable

• Sumerian
• Sumerology
• summa
• summa cum laude
• summarily
• summarisation
• summarise
• summarization
• summarize
• summary
• summary judgement
• summary judgment
• summary treatment
• summat
• summate
• summation
• summational
• summative
• summer
• summer camp
• summer cohosh
• summer crookneck
• summer cypress
• summer damask rose
• summer duck