Resisted leader of flock repeatedly going outside closed circle (6,3)

'resisted' is the definition.
(resist can mean to fend off)

'leader of flock repeatedly going outside closed circle' is the wordplay.
'flock repeatedly' can mean three replacements for 'flock'.
'leader of' suggests taking the first letters.
'going outside' is an insertion indicator (the word goes on the outside of inserted letters).
'closed' becomes 'ended' (I've seen this in another clue).
'circle' becomes 'O' (O is a circle).
The first letters of 'flock flock flock' is 'fff'.
'ended'+'o'='endedo'
'fff' placed around 'endedo' is 'FENDED OFF'.