New lager includes oxygen in abundance (6)
I believe the answer is:
galore
'in abundance' is the definition.
(I've seen this before)
'new lager includes oxygen' is the wordplay.
'new' indicates anagramming the letters.
'includes' indicates putting letters inside.
'oxygen' becomes 'O' (atomic symbol for oxygen).
'lager' with letters rearranged gives 'galre'.
'galre' going around 'o' is 'GALORE'.
(Other definitions for galore that I've seen before include "abundantly" , "Pussy ---, Bond girl" , "Lots of" , "In profusion" , "Aplenty" .)