Argued about when on weed regularly (8)
I believe the answer is:
reasoned
'argued' is the definition.
(I've seen this before)
'about when on weed regularly' is the wordplay.
'about' becomes 're' (regarding**).
'when' becomes 'as'.
'regularly' indicates alternate letters (regularly take one letter, leave next etc.).
The alternate letters of 'weed' are 'ed'.
're'+'as'+'on'+'ed'='REASONED'
(Other definitions for reasoned that I've seen before include "Performed brain operations" , "Logically valid" , "Argued or deduced" , "Argued logically" , "Debated in calm and logical way" .)