ferrule in British English
or ferule (ˈfɛruːl, -rəl)
noun1. a metal ring, tube, or cap placed over the end of a stick, handle, or post for added strength or stability or to increase wear
2. a side opening in a pipe that gives access for inspection or cleaning
3. a bush, gland, small length of tube, etc, esp one used for making a joint
verb4. (transitive) to equip (a stick, etc) with a ferrule