Starfleet's Captain Douglas? (4)

I believe the answer is:

kirk

I'm a little stuck... Click here to teach me more about this clue!

'captain douglas?' is the definition.
'kirk' can be an answer for 'captain' (I've seen this before). I'm not certain of the 'douglas?' bit.

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

Can you help me to learn more?

(Other definitions for kirk that I've seen before include "Church of Scotland" , "Star Trek captain - Scottish church" , "Presbyterian building?" , "Scots church" .)

I've seen this clue in The Sun.

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