noun
growing old together (as a couple)
Poetic term for a married couple aging together, often used in wedding contexts or well-wishes.
結婚式で「共白髪まで」と祝辞を述べた。
At the wedding, they gave a speech wishing the couple to grow old together.
noun
white hemp thread (betrothal gift symbolizing growing old together)
Traditional betrothal gift item; the white thread represents the hair of an elderly couple, symbolizing a wish for a long marriage.
One of the betrothal gifts is the white hemp thread.
Compound of 共 (together) and 白髪 (white hair). The exact historical derivation is uncertain, but the word has long been associated with marital longevity and betrothal customs.