Stupidly making any line crooked (7)
I believe the answer is:
inanely
'stupidly' is the definition.
(I've seen this before)
'any line crooked' is the wordplay.
'crooked' indicates anagramming the letters (a crooked or disrupted version of the letters).
'any'+'line'='anyline'
'anyline' with letters rearranged gives 'INANELY'.
'making' is the link.
(Other definitions for inanely that I've seen before include "In a fatuous manner" , "Stupidly" , "Vapidly" , "in a daft way" , "Senselessly" .)