Rodent played part in unpleasant situation (3,4)
I believe the answer is:
rat trap
'situation' is the definition.
(I have seen 'difficult situation' mean 'rat trap' so perhaps 'situation' could also mean 'rat trap')
'rodent played part in unpleasant' is the wordplay.
I cannot really understand how this works, but
'rodent' could be 'rat' (rat is a kind of rodent) and 'rat' is found in the answer.
an anagram of 'part' is 'trap' which is located in the answer.
This accounts for all the letters.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for rat trap that I've seen before include "difficult situation" , "pedal" , "might this stop his desertion?" , "rodent catcher" , "pest controller" .)