Noun
The act of nodding.
A very small libratory motion of the earth's axis, by which its inclination to the plane of the ecliptic is constantly varying by a small amount.
The motion of a flower in following the apparent movement of the sun, from the east in the morning to the west in the evening.
Circumnutation.
Source: Webster's dictionaryA pure nutation is a movement of a rotational axis such that the first Euler angle is constant. Source: Internet
Al-Batani's value, 54.5 arc-seconds per year, compares well to the current value of 49.8 arc-seconds per year (26,000 years for Earth's axis to round the circle of nutation ). Source: Internet
The component perpendicular to the ecliptic is known as the nutation in obliquity. Source: Internet
In simpler terms, nutation (and precession) values are important in observation from Earth for calculating the apparent positions of astronomical objects. Source: Internet
The component that works along the ecliptic is known as the nutation in longitude. Source: Internet
The true or instantaneous obliquity includes the nutation. Source: Internet