Pin inserted into a joint (6)

I believe the answer is:

skewer

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'pin' is the definition.
(I know that skewer is a type of pin)

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

(Other definitions for skewer that I've seen before include "The heart of kebab" , "Metal spit" , "Metal stick (that's more awry?)" , "more asymmetrical?" , "Pin for meat etc" .)

I've seen this clue in The Globe and Mail.

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