Thrown back from seashore, lobsters dance (6)
I believe the answer is:
bolero
'dance' is the definition.
(I know that bolero is a dance)
'thrown back from seashore lobsters' is the wordplay.
'thrown back' says the letters should be written backwards.
'from' indicates a hidden word.
'orelob' is hidden within 'seashore lobsters'.
'orelob' in reverse letter order is 'BOLERO'.
(Other definitions for bolero that I've seen before include "Genre of slow-tempo Latin music associated with Spain and Cuba" , "Famous Ravel work" , "Jacket not covering waist" , "Upper garment or music piece by Ravel" , "Ravel work; jacket" .)