Gather or bring together (6)
I believe the answer is:
muster
I believe this is a double definition.
'gather' is the first definition.
(I know that muster is a more specific form of the action gather)
'bring together' is the second definition.
(thesaurus)
(Other definitions for muster that I've seen before include "Bring (troops) together" , "Sample" , "marshal" , "Assemble, gather together" , "Mobilize" .)