Nu-tā'tion, n.

n. [Lat. nutatio, a nodding, from nutare, to nod; Fr. nutation.] 1. The act of nodding. [Rare.] So from the midmost the nutation spreads, Round and more round, o'er all the sea of heads. Pope.

2. (Astron.) A vibratory 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.) 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.