trio (n.)
- adaptation
- arrangement
- band
- brass
- clover
- coaction
- collaboration
- collectivism
- collusion
- combo
- commensalism
- communalism
- communism
- community
- complicity
- composition
- concert
- concord
- concordance
- concurrence
- cooperation
- cooperativeness
- descant
- deuce-ace
- duet
- duo
- ecumenicalism
- ecumenicism
- ecumenism
- ensemble
- esprit
- etude
- exercise
- fellowship
- group
- harmonization
- harmony
- invention
- leash
- morale
- mutualism
- mutuality
- nocturne
- octet
- opus
- orchestra
- orchestration
- piece
- production
- quartet
- quintet
- reciprocity
- score
- septet
- sestet
- sextet
- shamrock
- solidarity
- sonata
- sonatina
- strings
- study
- symbiosis
- symphony
- synergism
- synergy
- teamwork
- tercet
- ternary
- ternion
- terzetto
- three
- threesome
- tierce
- trefoil
- trey
- triad
- triangle
- tricorn
- trident
- trilogy
- trimester
- trine
- trinity
- triple
- triplet
- triplex
- tripod
- triptych
- trireme
- triskelion
- triumvirate
- trivet
- troika
- variation
- woodwind
- work
