honeymoon is the period of private celebration following the wedding, only between the couple, without the presence of third parties, such as children or relatives.
On their honeymoon, couples usually celebrate their new union with large trips, most of the times international. There are many hotels that have a great infrastructure to specifically receive this type of guests.
The honeymoon starts at wedding night, that is, the night after the couple's wedding ceremony.
Origin
There are several versions about how the honeymoon originated, one of them is that in Ancient Rome, people spread drops of honey on the threshold of the newlyweds' house.
Another version states that among the Germanic peoples, it was customary to get married on the new moon, and the couple took a mixture of water and honey, called mead, to drink in the moonlight.
The oldest version is from two thousand years before Christ, in Babylon, where normally the bride's father offered to the son-in-law mead, to be consumed within 30 days of the wedding, when the couple celebrated, just among themselves, the union matrimonial.
At the time, the counting of days was done by the lunar calendar, which is why this period of commemoration was known as the "honeymoon".
There was a popular tradition that newlywed couples should consume this drink during the first lunar cycle after the wedding to have their first child.
In English, the “honeymoon” is translated to honeymoon.
See also the meaning of wedding anniversary.