Everyone held back by master, a 14th-century reformer (7)

I believe the answer is:

lollard

'14th-century reformer' is the definition.
(type of religious former)

I don't understand the rest of the clue.

(Other definitions for lollard that I've seen before include "Radical Christian" , "Follower of John Wyclif" , "religious reformer" , "Follower of John Wycliffe" , "Wycliffite" .)

I've seen this clue in The Guardian.

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