Fellow resident concerned with psychological processes (8)
I believe the answer is:
conative
'concerned with psychological processes' is the definition.
The answer and definition are not the same part of speech. However, adjectives and past participle verbs sometimes define each other.
'fellow resident' is the wordplay.
'fellow' becomes 'co' (I've seen this in other clues).
'resident' becomes 'native' (I've seen this before).
'co'+'native'='CONATIVE'
Can you help me to learn more?
(Another definition for conative that I've seen is " leading to purposeful action".)