Where palm is available (2,4)
I believe the answer is:
on hand
'available' is the definition.
(similar in meaning)
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for on hand that I've seen before include "location of bananas?" , "just round the corner" , "Present or easily available" , "Where digital process is" , "Available like wedding ring?" .)