Store various hats that go on a swollen head (5)
I believe the answer is:
stash
'store' is the definition.
(stash is a kind of store)
'various hats that go on a swollen head' is the wordplay.
'various' is an anagram indicator.
'that go on' says to put letters next to each other.
'head' indicates taking the first letters.
The first letter of 'swollen' is 's'.
'hats'+'s'='hatss'
'hatss' is an anagram of 'STASH'.
(Other definitions for stash that I've seen before include "(Illegal) hoard" , "Secret hoard" , "Secret store (colloq.)" , "Stow; secret store" , "drug store" .)