Ladies' man from California briefly dated star (8)
I believe the answer is:
casanova
'ladies' man' is the definition.
(I've seen this in another clue)
'california briefly dated star' is the wordplay.
'california' becomes 'ca' (abbreviation).
'briefly' means to remove the last letter.
'dated' becomes 'saw' (see can mean to date romantically).
'star' becomes 'nova' (nova is a kind of star).
'saw' with its final letter taken off is 'sa'.
'ca'+'sa'+'nova'='CASANOVA'
'from' acts as a link.
(Other definitions for casanova that I've seen before include "18th century Italian lover" , "Legendary lover" , "Legendary Italian womaniser" , "Notorious Italian womaniser of 18th century" , "Amorous Venetian" .)