Dance, though Rachel and son not dancing (10)
I believe the answer is:
charleston
'dance' is the definition.
(charleston is a kind of dance)
'rachel and son not dancing' is the wordplay.
'and' means one lot of letters go next to another (I've seen this in other clues).
'son' becomes 's'.
'dancing' indicates anagramming the letters.
's'+'not'='snot'
'rachel' after 'snot' is 'snotrachel'.
'snotrachel' anagrammed gives 'CHARLESTON'.
'though' is the link.
(Other definitions for charleston that I've seen before include "Lively 1920s' dance" , "Nineteen twenties dance" , "American port" , "Town of South Carolina which gave its name to a 1920s dance craze" , "US city - 1920s' dance" .)