septet (n.)

• antistrophe
• book
• burden
• canto
• chorus
• coaction
• collaboration
• collectivism
• collusion
• commensalism
• communalism
• communism
• community
• complicity
• concert
• concord
• concordance
• concurrence
• cooperation
• cooperativeness
• couplet
• distich
• duet
• duo
• ecumenicalism
• ecumenicism
• ecumenism
• envoi
• esprit
• fellowship
• harmony
• heptad
• heptagon
• line
• measure
• morale
• mutualism
• mutuality
• octave
• octet
• quartet
• quatrain
• quintet
• reciprocity
• refrain
• sestet
• seven
• sevener
• sextet
• solidarity
• stanza
• stave
• strain
• strophe
• syllable
• symbiosis
• synergism
• synergy
• teamwork
• tercet
• terzetto
• trio
• triplet
• triumvirate
• troika
• verse
• week