Even one needs energy drink (8)
I believe the answer is:
smoothie
'drink' is the definition.
(smoothie is a type of drink)
'even one needs energy' is the wordplay.
'even' becomes 'smooth' (similar in meaning).
'one' becomes 'I' (Roman numeral).
'needs' is a charade indicator (letters next to each other).
'energy' becomes 'e' (physics symbol as in E=mcm).
'smooth'+'i'+'e'='SMOOTHIE'
(Other definitions for smoothie that I've seen before include "Drink made with pur?ed fruit" , "Thick, drink of pureed fruit" , "Fruit pured with milk" , "Sweet talker" , "Dairy fruit drink" .)