Place to keep one good plug (6)
I believe the answer is:
spigot
'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).
'i'+'g'='ig'
'spot' enclosing 'ig' is 'SPIGOT'.
(Other definitions for spigot that I've seen before include "Tap, faucet" , "Plug for a cask's vent hole" , "Small peg or plug" , "Tap for barrel" , "Regulator for controlling the flow of a liquid" .)