～団
～だん · ～dan · JLPT N2 · noun
party
～dan sounds like band: 楽団 gakudan is literally a music band
団 is the simplified form of 團: the enclosure 囗 around 專, which carries the sense of round or gathered. A 団 is people gathered into one body: 劇団 theatre troupe, 応援団 cheering squad, 消防団 fire brigade.