Strict-living sect discovered imprisoned by revolutionary spies (7)
I believe the answer is:
ascetic
'imprisoned by revolutionary spies' is the definition.
The answer and definition are not the same part of speech. However, adjectives and past participle verbs sometimes define each other.
'strict-living sect' is the wordplay.
I cannot quite see how this works, but
an anagram of 'sect' is 'scet' which is within the answer.
This may be the basis of the clue (or it may be nonsense).
'discovered' acts as a link.
Can you help me to learn more?
(Other definitions for ascetic that I've seen before include "Self-denying, often for religious reasons" , "he never imbibes" , "Hermit" , "Self-denying, leading severely simple life" , "Self-denying person who shuns ordinary pleasures" .)