Abstinent support nearly everybody downing dram (8)
I believe the answer is:
teetotal
'abstinent' is the definition.
(synonyms)
'support nearly everybody downing dram' is the wordplay.
'support' becomes 'tee' (tee is a kind of support).
'nearly' means to remove the last letter.
'everybody' becomes 'all' (all people).
'downing' means one lot of letters goes inside another (to down food or drink is to swallow it quickly).
'dram' becomes 'tot' (I've seen this in another clue).
'all' with its last letter taken off is 'al'.
'tee'+'al'='teeal'
'teeal' going around 'tot' is 'TEETOTAL'.
(Other definitions for teetotal that I've seen before include "Abstaining completely from alcohol" , "Abjuring alcohol" , "Pledged to abstain from alcohol" , "refusing to drink" , "Avoiding alcohol" .)