Peasants hold out when surrounded by police (11)

'peasants' is the definition.
Although both the answer and definition are plural nouns, I cannot see how they can define each other.

'hold out when surrounded by police' is the wordplay.
'out' indicates an anagram (out can mean wrong or inaccurate).
'when surrounded by' is an insertion indicator.
'police' becomes 'coppers' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'hold' with letters rearranged gives 'lodh'.
'lodh' put into 'coppers' is 'CLODHOPPERS'.

Can you help me to learn more?