Pūrṇimā (Sanskrit: पूर्णिमा) is the word for full moon in Sanskrit

The day of Purnima is the day (Tithi) in each month when the full moon occurs, and marks the division in each month between the two lunar fortnights (paksha), and the Moon is aligned exactly in a straight line, called a syzygy, with the Sun and Earth

Full moon is considered the third of the four primary phases of the Moon; the other three phases are new moon, first quarter moon, and third quarter moon

The full moon shows 100% illumination, causes high tides, and can concur with lunar eclipses