All 11 Uses

however
in
Rebecca, by Daphne du Maurier
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The daffodils were in bloom, stirring in the evening breeze, golden heads cupped upon lean stalks, and however many you might pick there would be no thinning of the ranks, they were massed like an army, shoulder to shoulder.
Chpt 4

however = regardless of how
This has been ours, however brief the time.
Chpt 6
'However, it's a very charming room,' I said, 'and I'm sure I shall be comfortable.'
Chpt 7

however = though (used to connect contrasting ideas)
Of course I've never had anything to do with her, and I don't think I ever want to either. However, she's always been very civil to me.
Chpt 9 *
'Mrs Danvers,' he said, 'can you think of any reason, however remote, why Mrs de Winter should have taken her own life?
Chpt 24 *

however = regardless of how
Whoever lived within its walls, whatever trouble there was and strife, however much uneasiness and pain, no matter what tears were shed, what sorrows borne, the peace of Manderley could not be broken or the loveliness destroyed.
Chpt 26
However, I was younger then.†
Chpt 3
However, it was simpler not to say anything.†
Chpt 15
However it can't be helped.'†
Chpt 17 *
However, once the inquest is over you must both forget all about it.†
Chpt 21
However, never mind about that now.†
Chpt 27

Definitions:

(1) (however as in: However, complications may...)
though (or another expression that connects contrasting ideas)

Based on idea 1 we might not expect idea 2, but this is a way of saying that even though idea 1 exists, we still have idea 2. Synonyms include in spite of that, despite that, nevertheless, nonetheless, on the other hand, in contrast and but.
(2) (however as in: However much she tried...)
to whatever degree (regardless of how much; or whatever unspecified amount)
(3) (however as in: However you do it, get it done!)
in whatever way
(4) (meaning too rare to warrant focus)
Much more rarely (and arguably incorrectly), however can be used to intensify the word how, as when one says "However did you find her?" Grammarians would suggest using two words for that usage: "How ever did you find her?"