Relaxed, finding heartless friend in back of chair (5)
I believe the answer is:
splat
'back of chair' is the definition.
The answer and definition can be both related to change as well as being verbs in their base form.
Perhaps they are linked in a way I don't understand?
'relaxed finding heartless friend in' is the wordplay.
'relaxed finding' becomes 'sat' (I can't justify this - if you can you should believe this answer much more).
'heartless' means to remove the middle letters.
'friend' becomes 'pal' (pal can mean a friend).
'in' is an insertion indicator.
'pal' with its centre removed is 'pl'.
'sat' placed around 'pl' is 'SPLAT'.
Can you help me to learn more?
(Other definitions for splat that I've seen before include "Wet slapping sound" , "Sound of a wet and squishy impact" , "Sound of a soft wet landing" , "amusing noise" , "Noise on landing" .)