A thoughtful intention (4)
I believe the answer is:
idea
'intention' is the definition.
(idea is a kind of intention)
'a thoughtful' is the wordplay.
I cannot really see how this works, but
'a' is found in the answer.
The remaining letters 'ide' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for idea that I've seen before include "It comes to mind" , "Thought; concept" , "Fancy" , "Aim" , "Theory" .)