Volunteers and student with monarch are chatting (7)
I believe the answer is:
talking
'are chatting' is the definition.
(I've seen this before)
'volunteers and student with monarch' is the wordplay.
'volunteers' becomes 'TA' (abbreviation for Territorial Army).
'and' means one lot of letters go next to another.
'student' becomes 'L' (as in L-plates for learner drivers).
'with' says to put letters next to each other.
'monarch' becomes 'king' (king is a kind of monarch).
'ta'+'l'+'king'='TALKING'
(Other definitions for talking that I've seen before include "Speaking" , "Chatting" , "Verbalising" , "Conversing" .)