Drink — mine is raised on request mostly (6)
I believe the answer is:
tipple
'drink mine' is the definition.
'tipple' can be an answer for 'drink' (tippling is a kind of drinking). I'm not certain of the 'mine' bit.
'raised on request mostly' is the wordplay.
'raised on' becomes 'tip' (I can't justify this - if you can you should give a lot more credence to this answer).
'request' becomes 'plea' (plea is a kind of request).
'mostly' means to remove the last letter (most but not all of the word).
'plea' with its last letter taken off is 'ple'.
'tip'+'ple'='TIPPLE'
'is' acts as a link.
Can you help me to learn more?
(Other definitions for tipple that I've seen before include "Alcoholic liquor" , "Habitually drink in small quantities" , "(Regular) alcoholic drink" , "(Favourite) drink" , "pint?" .)