1. vacation for newly-married couple: a period of time spent alone together, especially away, by a newly-married couple, usually immediately following the wedding or reception
2. period of good feeling: a short period of harmony or goodwill at the beginning of a relationship, especially in politics or business
[Mid-16th century. Originally "waning affection," from the idea that although married love is at first as sweet as honey, it soon wanes like the moon]