Though abstinent initially, engineer drunk bottles (6)
I believe the answer is:
albeit
'though' is the definition.
(I've seen this before)
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for albeit that I've seen before include "Although, nevertheless" , "In spite of the fact that" , "Although, since" , "A literary although" , "Although, inasmuch as" .)