Guarding posh spoiled girl tends to anger (10)

I believe the answer is:

disgruntle

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'anger' is the definition.
Both the definition and answer are verbs in their base form.
Maybe they are linked in a way I don't understand?

'guarding posh spoiled girl tends' is the wordplay.
'guarding' is an insertion indicator.
'posh' becomes 'u' (abbreviation for upper-class - opposite to non-u).
'spoiled' indicates an anagram.
'girl'+'tends'='girltends'
'girltends' is an anagram of 'disgrntle'.
'u' inserted within 'disgrntle' is 'DISGRUNTLE'.

'to' acts as a link.

Can you help me to learn more?

I've seen this clue in The Guardian.

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