Marvin was one disheartened android in programme (6)
I believe the answer is:
shadow
'marvin' is the definition.
Both the answer and definition are singular nouns.
Maybe they are linked in a way I don't understand?
'one disheartened android in programme' is the wordplay.
'one disheartened' suggests removing the centre (the middle or heart is removed).
'in' is an insertion indicator.
'programme' becomes 'show' (I've seen this before).
'android' with its centre removed is 'ad'.
'ad' put within 'show' is 'SHADOW'.
'was' acts as a link.
Can you help me to learn more?
(Other definitions for shadow that I've seen before include "Follow closely - dark image - opposition" , "Secret follower" , "Follow closely; pale imitation" , "Inseparable companion; dark patch" , "Image caused by obscuring of light" .)