tie in (v.)
- accord
- affect
- affiliate
- ally
- amalgamate
- associate
- band
- bond
- bunch
- cabal
- centralize
- club
- coact
- coalesce
- collaborate
- collude
- combine
- concern
- concert
- concord
- concur
- confederate
- connect
- consociate
- consolidate
- conspire
- cooperate
- couple
- demand
- federalize
- federate
- fuse
- gang
- harmonize
- intercourse
- interest
- involve
- join
- league
- link
- market
- marry
- merge
- organize
- pair
- partner
- reciprocate
- regard
- respect
- retail
- sale
- splice
- tie
- touch
- unionize
- unite
- wed
- wholesale