Compels to join the troops (8)
I believe the answer is:
dragoons
'compels' is the definition.
The definition and answer can be both to do with social activities as well as being verbs in their -s form.
Perhaps you can see a link between them that I can't see?
'join the troops' is the wordplay.
I cannot quite see how this works, but
'troops' could be 'ra' (Royal Artillery) and 'ra' is found within the answer.
This may be the basis of clue (or it may be nonsense).
'to' is the link.
Can you help me to learn more?
(Other definitions for dragoons that I've seen before include "Forces" , "Heavily armed cavalrymen" , "Compels by force; soldier" , "Bullies" .)