Out of humour, tiddler sung woefully (11)

I believe the answer is:

disgruntled

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'out' is the definition.
Both the definition and answer are adjectives. Maybe there's a link between them I don't understand?

'humour tiddler sung woefully' is the wordplay.
'tiddler sung' anagrams to 'DISGRUNTLED'.
But, I'm not sure how this is indicated.

'of' is the link.

Can you help me to learn more?

(Other definitions for disgruntled that I've seen before include "Angry or dissatisfied" , "Sulky" , "Cheesed off" , "Grumpy" , "Unhappy" .)

I've seen this clue in the Sydney Morning Herald.

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