Old soldiers dance (7)
I believe the answer is:
lancers
This clue might be a double definition.
'old soldiers' is the first definition.
'lancers' can be an answer for 'soldiers' (lancer is a kind of soldier). I am not certain of the 'old' bit.
'dance' is the second definition.
(lancers is a kind of dance)
Can you help me to learn more?
(Other definitions for lancers that I've seen before include "Old regiment; dance" , "Quadrille for eight/sixteen pairs" , "Regimental" , "Soldiers with spears on horseback" , "People performing opening acts in theatre" .)