rotula /rotˈū-lə/

1. The knee-cap (anatomy)
2. A radial piece of Aristotle's lantern in sea-urchins (zoology)

• night-porters
• night-rail
• night-rails
• night-raven
• night-ravens
• night-rest
• night-rests
• nightrider
• nightriders
• night-robe
• night-robes
• night-rule
• night-rules
• nights
• night safe
• night safes
• night school
• night schools
• night-season
• night-seasons
• nightshade
• nightshades
• night shift
• night shifts
• nightshirt