Lap dance blunder (5,4)
I believe the answer is:
round trip
'lap' is the definition.
(thesaurus)
'dance blunder' is the wordplay.
'dance' becomes 'round' (round dance is a kind of dance).
'blunder' becomes 'trip' (trip is a kind of blunder).
'round'+'trip'='ROUND-TRIP'
(Other definitions for round trip that I've seen before include "collecting drinks from the bar?" , "tour" , "bar and back?" , "kind of voyage" , "going both ways" .)