He'll put a bit of ice in a drink for you (6)
I believe the answer is:
waiter
'he'll put a' is the definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.
'bit of ice in a drink for you' is the wordplay.
I cannot quite see how this works, but
'bit' could be 'i' (resembles 1, a binary digit or bit) and 'i' is found within the answer.
'drink' could be 'water' (water is an example) and 'water' is present in the leftover letters.
This accounts for all the letters.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for waiter that I've seen before include "Restaurant staff member" , "Herr Ober (Ger.)" , "Restaurant employee" , "Servant in bar" , "Attendant" .)