For preference, take a bite out of a choc-ice (6)
I believe the answer is:
choice
'for preference' is the definition.
(I've seen this before)
'a bite out of a choc-ice' is the wordplay.
'bite' becomes 'chomp' (synonyms).
'out of' suggests deleting specific letters.
'a' becomes 'amp' (A is the symbol for the amp or ampere).
'choc-ice' becomes 'ice' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'a'+'chomp'='achomp'
'achomp' with 'amp' removed is 'cho'.
'cho'+'ice'='CHOICE'
'take' acts as a link.
Can you help me to learn more?
(Other definitions for choice that I've seen before include "Very good" , "Pick" , "Possibility" , "Top quality" , "Act or power of selecting" .)