Heard drinks could cause temporary lowering of standards (5)
I believe the answer is:
lapse
'cause temporary lowering of standards' is the definition.
The answer and definition can be both acts as well as being singular nouns.
Perhaps there's an association between them I don't understand?
'heard drinks' is the wordplay.
'heard' indicates a 'sounds like' (homophone) clue.
'drinks' becomes 'laps' (lapping is a kind of drinking).
'laps' sounds like 'LAPSE'.
'could' is the link.
Can you help me to learn more?
(Other definitions for lapse that I've seen before include "Slip-up" , "Regress" , "Go back to bad behaviour" , "Pleas (anag)" , "Brief failure (of concentration)" .)