Pretentious type took action when talked about (5)

I believe the answer is:

pseud

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'pretentious type' is the definition.
(I've seen this before)

I don't understand how the rest of the clue works.

(Other definitions for pseud that I've seen before include "Pretentious fraud" , "Pretentious type" , "Pretentious sort" , "pretentious woman" , "Pretender - fraud" .)

I've seen this clue in The Irish Times.

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