Embarrassed Barty with a drug (7)
I believe the answer is:
ashamed
'embarrassed' is the definition.
(similar in meaning)
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for ashamed that I've seen before include "'Embarrassed, guilty (7)'" , "Humiliated" , "Feeling remorse and guilt" , "Overcome by remorse or guilt" , "Mortified or consciencestricken" .)