Meanly lent gun out - not chivalrous (13)

I believe the answer is:

ungentlemanly

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'not chivalrous' is the definition.
I can't judge whether this defines the answer.

'meanly lent gun out' is the wordplay.
'out' is an anagram indicator (out can mean wrong or inaccurate).
'meanly'+'lent'+'gun'='meanlylentgun'
'meanlylentgun' anagrammed gives 'UNGENTLEMANLY'.

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(Other definitions for ungentlemanly that I've seen before include "Lacking refinement" , "possibly ladylike" .)

I've seen this clue in The Daily Express.

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