Mistakes catching Quisling in time (6)
I believe the answer is:
errata
'mistakes' is the definition.
(erratum is a kind of mistake)
'quisling in time' is the wordplay.
'quisling' becomes 'rat' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'in' is an insertion indicator.
'time' becomes 'era' (I've seen this before).
'rat' put into 'era' is 'ERRATA'.
'catching' acts as a link.
Can you help me to learn more?
(Other definitions for errata that I've seen before include "Corrigenda" , "Slips" , "Mistakes in printed matter" , "List of printing mistakes" , "Feeling nausea" .)