noun
old relationship; old acquaintance
Refers to a connection or friendship from the past; somewhat literary or formal in tone.
旧縁を頼って上京した。
I came to Tokyo relying on an old acquaintance.
旧縁のある者同士で集まった。
People with old ties got together.
Compound of 旧 (old, former) and 縁 (connection, bond). The exact historical derivation is uncertain, but the meaning is transparent from its components.