1. The upper chamber of each half of the heart
   - atrium of the heart

Type of: atrium

• Northumberland
• Northumbria
• northward
• northwards
• northwest
• northwest by north
• northwest by west
• Northwest Passage
• Northwest Territories
• northwest wind
• northwester
• northwesterly
• northwestern
• northwestern United States
• northwestward
• northwestwardly
• nortriptyline
• Noruz
• Norvasc
• Norvir
• Norway
• Norway lobster
• Norway maple
• Norway rat
• Norway spruce