Start of climb up pole for prizes (4)
I believe the answer is:
cups
'for prizes' is the definition.
(cup is a kind of prize)
'start of climb up pole' is the wordplay.
'start of' says to take the initial letters.
'pole' becomes 's' (abbreviation for South, as in South Pole).
The initial letter of 'climb' is 'c'.
'c'+'up'+'s'='CUPS'
(Other definitions for cups that I've seen before include "Small open drinks containers" , "In these, you're tiddly" , "Trophies" , "silverware" , "Drinking vessels" .)