Copper embraced by slightly drunk element (7)
I believe the answer is:
mercury
'element' is the definition.
(mercury is a kind of element)
'copper embraced by slightly drunk' is the wordplay.
'copper' becomes 'cu' (chemical symbol).
'embraced by' indicates putting letters inside.
'slightly drunk' becomes 'merry' (I've seen this in other clues).
'cu' placed inside 'merry' is 'MERCURY'.
(Other definitions for mercury that I've seen before include "Messenger of the Gods, or a chemical element" , "First rock from the Sun - Hg" , "one in distant orbit?" , "Element, symbol Hg" , "Quicksilver" .)