The act of nodding. "So from the midmost the nutation spreads, Round and more round, o'er all the sea of heads."
2.
(Astron.) 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.
3.
(Bot.)
(a)
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.
