noun
second honeymoon
A trip taken by a married couple to rekindle their relationship, often after many years of marriage. Less common than セカンドハネムーン.
両親は結婚30周年に旧婚旅行でハワイに行った。
My parents went on a second honeymoon to Hawaii for their 30th anniversary.
Compound of 旧 (former, old) + 婚 (marriage) + 旅行 (travel). The exact origin is uncertain, but it appears to be a modern coinage modeled after 新婚旅行 (honeymoon).