Beer taken on, on one's own (5)
I believe the answer is:
alone
'on one's own' is the definition.
(I've seen this before)
'beer taken on' is the wordplay.
'beer' becomes 'ale' (type of beer).
'taken' indicates putting letters inside.
'ale' going around 'on' is 'ALONE'.
(Other definitions for alone that I've seen before include "without another" , "Without others being involved" , "Singly" , "On one's own" , "Note of charges" .)