Refers to the trip or period just after a wedding. The loanword ハネムーン is also common.
See also: ハネムーン
新婚夫婦は蜜月でハワイに行った。
The newlyweds went to Hawaii for their honeymoon.
honeymoon period; intimate relationship
Figurative use for a harmonious early stage of a relationship, project, or political term. Often used in the phrase 蜜月関係.
新社長と組合の間には今のところ蜜月関係が続いている。
For now, a honeymoon relationship continues between the new president and the union.
honeymoon trip
honeymoon period
Compound of 蜜 (honey, sweetness) and 月 (month), likely a calque of English 'honeymoon'. The figurative sense developed from the idea of a sweet, harmonious period.