full moon

noun

1. the moon when the whole of its disk is illuminated, occurring when in opposition to the sun.
2. the phase of the moon at this time.

full moon

noun

1. one of the four phases of the moon, occurring when the earth lies between the sun and the moon so that the moon is visible as a fully illuminated disc
2. the moon in this phase
3. the time at which this occurs

full moon

/ fl /

1. The phase of the Moon in which it is visible as a fully illuminated disk. This phase occurs when the Moon is on the opposite side of Earth as the Sun and is not in Earth's shadow.
2. See more at moonCompare new moon

Word History and Origins

Origin of full moon¹

before 1000; Middle English ful moyne, Old English fulles monan

Example Sentences

The highest tides — king tides — are seen during new and full moons when the sun, Earth and moon are in a line.

From Los Angeles Times

The Moon will be in a waxing gibbous phase – going from half moon to full moon.

From BBC

If you catch a glimpse of the full moon in the next couple of nights, you might notice how bright it is.

From BBC

A supermoon occurs when the full moon is at its closest possible point to Earth, which causes it to appear 14% larger and 30% brighter than the faintest moon of the year, according to NASA.

From Los Angeles Times

The harvest moon refers to the full moon that appears closest to the fall equinox.

From Los Angeles Times