A fitting end to a pipe (3)
I believe the answer is:
tap
'pipe' is the definition.
(thesaurus)
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for tap that I've seen before include "Draw upon Pat" , "In America, it's a spigot" , "Make use of; water from it" , "Stopper enabling withdrawal of liquid" , "British faucet" .)