Thoughtful writers I have seen (7)
I believe the answer is:
pensive
'thoughtful' is the definition.
(similar in meaning)
'writers i have seen' is the wordplay.
'writers' becomes 'pens' (writing implements).
'have' says to put letters next to each other.
'seen' becomes 've' (I can't explain this - if you can you should believe this answer much more).
'pens'+'i'+'ve'='PENSIVE'
Can you help me to learn more?
(Other definitions for pensive that I've seen before include "Deeply thoughtful" , "Preoccupied" , "Meditative" , "Introspective, maybe moody" , "Thinking deeply" .)