Struggle for words seeing line adopted by developer (8)
I believe the answer is:
flounder
'struggle for words' is the definition.
'line adopted by developer' is the wordplay.
'line' becomes 'l'.
'adopted by' means one lot of letters goes inside another (I've seen this in other clues).
'developer' becomes 'founder'.
'l' inserted into 'founder' is 'FLOUNDER'.
'seeing' is the link.
(Other definitions for flounder that I've seen before include "Fish -- stumble helplessly" , "Struggle clumsily - flatfish" , "swimmer in the sea" , "Stagger clumsily in mud (or water)" , "Move clumsily like flatfish?" .)