Definitions

1. noun

A day that is a conjunction of a full moon and a new moon; in other words, a day that is neither entirely illuminated by the full moon nor entirely in darkness, due to the timing of the new moon in the same lunar cycle.

“The plenilunal day was a rare and magical occurrence that inspired many artists throughout history.”

2. adjective

Relating to or characteristic of the conjunction of a full moon and a new moon.

“The plenilunal landscape was a place of mystery and enchantment.”