白頭到老 (baak6 tau4 dou3 lou5) — (to live together until the) white hairs of old age, that is, to live to a ripe old age in conjugal bliss in Cantonese
baakˍ₆白tauˎ₄頭dou˗₃到louˏ₅老简 白头到老
Mandarin Pinyin: bai2 tou2 dao4 lao3
Meaning of 白頭到老
noun(to live together until the) white hairs of old age, that is, to live to a ripe old age in conjugal bliss