Excluding huge vacuous items in copy (11)

'excluding' is the definition.
(ostracising is a kind of excluding)

'huge vacuous items in copy' is the wordplay.
'huge' becomes 'os' (abbreviation for outsize).
'vacuous' says to hollow out the word (remove centre letters).
'in' means one lot of letters goes inside another.
'copy' becomes 'tracing' (I've seen this before).
'items' with its centre removed is 'is'.
'is' put into 'tracing' is 'tracising'.
'os'+'tracising'='OSTRACISING'