So from the midmost the nutation spreads, Round and
more round, o'er all the sea of heads. --Pope.
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.
(b) Circumnutation.