Olive kept a dram processed as concentrated drink (10,4)
I believe the answer is:
evaporated milk
'concentrated drink' is the definition.
'evaporated milk' can be an answer for 'drink' (evaporated milk is a kind of drink). I am not sure about the 'concentrated' bit.
'olive kept a dram processed' is the wordplay.
'processed' is an anagram indicator.
'olive'+'kept'+'a'+'dram'='olivekeptadram'
'olivekeptadram' is an anagram of 'EVAPORATED MILK'.
'as' acts as a link.
Can you help me to learn more?
(Another definition for evaporated milk that I've seen is " food".)