1. Existing as an essential constituent or characteristic
   - built-in, constitutional, inherent, integral

See also: intrinsic, intrinsical

• RTLT
• Ru
• RU 486
• Ruanda
• Ruandan
• rub
• Rub al-Khali
• rub along
• rub off
• rub out
• rub up
• rub-a-dub
• rubai
• rubato
• rubber
• rubber band
• rubber boa
• rubber boot
• rubber bullet
• rubber cement
• rubber check
• rubber cheque
• rubber eraser
• rubber plant
• rubber tire