Shut up one married male university radical (7)
I believe the answer is:
immured
'shut up' is the definition.
The answer and definition are different parts of speech. However, past participle verbs and adjectives occasionally define each other.
'one married male university radical' is the wordplay.
'one' becomes 'i' (Roman numeral).
'married' becomes 'm' (abbreviation, e.g. in genealogy).
'male' becomes 'm' (common abbreviation).
'university' becomes 'U' (abbreviation for university).
'radical' becomes 'red' (red can mean a communist).
'i'+'m'+'m'+'u'+'red'='IMMURED'
Can you help me to learn more?
(Other definitions for immured that I've seen before include "Enclosed or imprisoned" , "Imprisoned, shut in" , "Locked up in jail" , "Incarcerated, walled up" , "Incarcerated, put behind bars" .)