Being dry, wild duck swallows energy drink (8)
I believe the answer is:
teetotal
'being dry' is the definition.
(synonyms)
'wild duck swallows energy drink' is the wordplay.
'wild duck' becomes 'teal' (I've seen this in another clue).
'swallows' indicates putting letters inside.
'energy' becomes 'e' (physics symbol as in E=mc2).
'drink' becomes 'tot' (a small alcoholic drink).
'e'+'tot'='etot'
'teal' enclosing 'etot' is 'TEETOTAL'.
(Other definitions for teetotal that I've seen before include "Abstention from alcoholic drink" , "Taking no alcohol" , "Completely dry" , "Not touching a drop" , "Never drinking alcohol" .)