D defs.my
Entry 3 senses Webster, 1913

Nutation

· Nu·ta·tion · IPA
01 n. The act of nodding.
  1. 1.
    The act of nodding.
    “So from the midmost the nutation spreads, Round and more round, o'er all the sea of heads.” Pope.
  2. 2.
    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.(Astron.)
  3. 3.
    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.(Bot.)