Compound left by smoker of marijuana? (6)
I believe the answer is:
potash
'compound left' is the definition.
'potash' can be an answer for 'compound' (I've seen this before). I'm not certain of the 'left' bit.
'by smoker of marijuana?' is the wordplay.
'by' says to put letters next to each other.
'smoker of' becomes 'ash' (I can't justify this - if you can you should believe this answer much more).
'marijuana?' becomes 'pot' (slang term for marijuana).
'ash' put after 'pot' is 'POTASH'.
Can you help me to learn more?
(Other definitions for potash that I've seen before include "field dressing" , "feed in bed?" , "Type of fertiliser" , "Potassium carbonate or hydroxide" , "Alkali used as fertiliser" .)