The term "quarter-moons" can refer to the shape of the moon during its first and third quarters, when it appears as a half-circle. However, there are several other synonyms that can be used to describe this lunar phase. These include "half-moon," "demi-lune," "semi-circle," and "hemisphere." In some cultures, the first quarter moon is called "waxing crescent," while the third quarter moon is known as "waning gibbous." No matter the term used, the quarter-moon phase is an important indicator of the moon's changing position in the sky and serves as a valuable tool for astronomers, astrologers, and casual skywatchers alike.