accord
act in concert
act together
affiliate
agree
ally
amalgamate
associate
band
band together
be in cahoots
be in league
club together
coadunate
coalesce
coincide
collaborate
collude
combine
compel
concert
concord
concur
confederate
conjoin
connive
consolidate
conspire
cooperate
correspond
do business with
dovetail
drive
engage
federate
force
fuse
get heads together
get together
go partners
hang together
happen together
harmonize
hold together
hook up
interact
interchange
interlace
intermesh
act
move