also: たれえい
noun
hanging tail (of a traditional Japanese hat); drooping tail
Refers to the long, trailing fabric tail of a formal court cap (冠) or similar headgear, especially in historical or ceremonial contexts.
束帯姿の冠からは、長い垂纓が背中に垂れている。
From the court cap of the sokutai attire, a long hanging tail hangs down the back.
冠 is the general term for a traditional cap or crown, while 垂纓 specifically refers to the hanging tail attached to such headgear.
Compound of 垂 (hanging) and 纓 (cord or tail of a cap). The exact historical derivation is uncertain, but the term is conventionally associated with the trailing ornament of formal headwear.