One keeps stocking up pubs, periodically interrupting consumer (9)
I believe the answer is:
suspender
'one keeps stocking up' is the definition.
I can't tell whether this defines the answer.
'pubs periodically interrupting consumer' is the wordplay.
'periodically' indicates alternate letters (letters must be selected 'every so often').
'interrupting' is an insertion indicator.
'consumer' becomes 'spender' (spender is a kind of consumer).
The alternate letters of 'pubs' are 'us'.
'us' put inside 'spender' is 'SUSPENDER'.
Can you help me to learn more?
(Other definitions for suspender that I've seen before include "material support" , "One responsible for hold-up" , "One that supports stocking" , "Strap to hold up a stocking" , "hangman?" .)