Swilling poteen, I got flush - sorry, that came out wrong (4,2,3,6)
I believe the answer is:
slip of the tongue
'swilling poteen i got flush sorry that came out wrong' is the definition.
Although both the answer and definition are singular nouns, I can't see how they can define each other.
'swilling poteen i got flush' is the wordplay.
'swilling' indicates an anagram (swill can mean to stir or swirl round).
'poteen'+'i'+'got'+'flush'='poteenigotflush'
'poteenigotflush' is an anagram of 'SLIP OF THE TONGUE'.
Can you help me to learn more?
(Other definitions for slip of the tongue that I've seen before include "mistake one hears" , "vocal error" , "Error in words" , "a small error" .)