See something held in palm (4)
I believe the answer is:
date
'palm' is the definition.
(date palm is a kind of palm)
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for date that I've seen before include "Estimate age of" , "Romantic appointment" , "sell-by, for example" , "Appointment - fruit of palm" , "Fruit with stone" .)