Place to keep one good plug (6)
I believe the answer is:
Here is my best explanation:
'plug' is the definition.
(spigot is a kind of plug)
'place to keep one good' is the wordplay.
'place' becomes 'spot' ('spot' can be a synonym of 'place'**).
'to keep' is an insertion indicator.
'one' becomes 'i' (Roman numeral).
'good' becomes 'g' (abbreviation).
'spot' enclosing 'ig' is 'SPIGOT'.
(Other definitions for spigot that I've seen before include "Plug for a cask's vent hole", "Cask's plug", "Peg to control the flow of a tap", "Peg that stops the vent of a cask", "Device for stopping", "Peg to seal vent in cask", "Tap fitted to a cask", "Tap, faucet", "Pigs to vent-peg" and "Small peg or plug".)