What does "nutation" mean?

Nutation: (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.

Additional senses

  1. 2.(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.

Sources