A bloomer most companions would find disturbing? (7)

I believe the answer is:

campion

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'a bloomer' is the definition.
(I know that campion is a type of bloomer)

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

Can you help me to learn more?

(Other definitions for campion that I've seen before include "Film director" , "Plant with pink or white flowers" , "Edmund ---, martyr; Thomas ---, poet/lute composer" , "Wayside flower" , "Here's one blooming" .)

I've seen this clue in the Evening Standard.

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