Quite the opposite of true humility (5,7)
I believe the answer is:
false modesty
'quite' is the definition.
I don't know anything about this answer so I can't tell whether it can be defined by this definition.
'opposite of true humility' is the wordplay.
'opposite of true' becomes 'false' ('false' is the opposite to 'true').
'humility' becomes 'modesty' (I've seen this before).
'false'+'modesty'='FALSE MODESTY'
'the' acts as a link.
Can you help me to learn more?
(Another definition for false modesty that I've seen is " Pretence of not being pretentious?".)