Lass arranged a dance (5)
I believe the answer is:
salsa
'dance' is the definition.
(type of dance)
'lass arranged a' is the wordplay.
'arranged' indicates anagramming the letters (letters rearranged).
'lass' with letters rearranged gives 'sals'.
'sals'+'a'='SALSA'
(Other definitions for salsa that I've seen before include "Dance or a dip?" , "that's hot and saucy?" , "Cuban dance music or spicy sauce" , "Latin-American dance" , "Latin American dance music" .)