Hide at one time in California (7)
I believe the answer is:
conceal
'hide' is the definition.
(I know that hide can be written as conceal)
'one time in california' is the wordplay.
'one time' becomes 'once' (synonyms).
'in' means one lot of letters goes inside another.
'california' becomes 'cal' (short for California).
'once' going within 'cal' is 'CONCEAL'.
'at' is the link.
(Other definitions for conceal that I've seen before include "Place out of sight" , "Keep out of sight" , "Hide, cover" , "Screen" , "hush up!" .)