Party drug: after small quantity, I felt the hit (6)
I believe the answer is:
touche
'i felt the hit' is the definition.
I don't know anything about this answer so I can't judge whether it can be defined by this definition.
'party drug after small quantity' is the wordplay.
'party drug' becomes 'e' (E is another name for ecstasy. I am not sure about the 'party' bit.).
'after' means one lot of letters go next to another.
'small quantity' becomes 'touch' (I've seen this before).
'e' put after 'touch' is 'TOUCHE'.
Can you help me to learn more?
(Other definitions for touche that I've seen before include "Fencer's shout" , "Acknowledgment of a hit in fencing" , "You got me" , "Acknowledgement of fencing hit or valid criticism" , "Acknowledgement of a good point" .)