coact (v.)

• accord
• affiliate
• agree
• ally
• amalgamate
• associate
• band
• coalesce
• coincide
• collaborate
• collude
• combine
• concert
• concord
• concur
• confederate
• conjoin
• connive
• consolidate
• conspire
• cooperate
• correspond
• dovetail
• engage
• federate
• fuse
• harmonize
• interact
• interchange
• interlace
• intertwine
• interweave
• join
• league
• merge
• mesh
• mortise
• partner
• reciprocate
• synchronize
• unite