Drinking beer, work steadily but dimly (6)
I believe the answer is:
palely
'dimly' is the definition.
(I know that dimly can be written as palely)
'drinking beer work steadily' is the wordplay.
'drinking' means one lot of letters goes inside another (inserted letters are consumed or drunk).
'beer' becomes 'ale' (type of beer).
'work steadily' becomes 'ply' (as in plying one's trade).
'ale' inserted within 'ply' is 'PALELY'.
'but' acts as a link.
(Other definitions for palely that I've seen before include "In a colourless manner lacking vitality or interest" , "in unimpressive manner" , "somewhat indistinctly" , "O what can ail thee, knight at arms, / Alone and ... loitering? (Keats)" .)