1. Situated at or extending to great depth; too deep to have been sounded or plumbed
   "unplumbed depths of the sea"
   - profound, unfathomed, unsounded

See also: deep

• fallaciousness
• fallacy
• fallal
• fallback
• fallboard
• fallen
• fallen angel
• fallen arch
• faller
• fallibility
• fallible
• fallibly
• falling
• falling off
• falling out
• falling star
• falloff
• Fallopian tube
• Fallopio
• Fallopius
• Fallot
• Fallot's syndrome
• Fallot's tetralogy
• fallout
• fallout shelter