They last only a short time as official records (7)
I believe the answer is:
minutes
'records' is the definition.
(minute is a kind of record)
'they last only a short time as official' is the wordplay.
I cannot quite see how this works, but
'last' could be 't' (I've seen this in other clues) and 't' is found in the answer.
'time' could be 'min' (short for minute) and 'min' is found in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for minutes that I've seen before include "Record of a meeting" , "Units of time" , "Written account of a meeting" , "summary" , "Record of a meeting's decisions" .)