ferrule /ferˈool, -əl/

1. A metal band, ring or cap on the tip of a stick, etc for reinforcing it
2. A threaded cylindrical fitting for joining two pipes or rods

• focalization
• focalizations
• focalize
• focalized
• focalizes
• focalizing
• focal length
• focal lengths
• focally
• focal plane
• focal planes
• focal-plane shutter
• focal-plane shutters
• focal point
• focal points
• foci
• focimeter
• focimeters
• fo'c'sle
• focus
• focused
• focuses
• focus fund
• focus funds
• focus group