Get old, fat, see (4)
I believe the answer is:
date
'see' is the definition.
(I know that see can be written as date)
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for date that I've seen before include "Sweet edible fruit" , "Specified day" , "Year or day when an event occurred" , "Small fruit or social appointment" , "The fruit for a social engagement" .)