Nutation
/nuːˈteɪʃən/noun
A regular wavering or oscillation in the orientation of a rotating body, especially the slight bobbing of Earth’s axis.
Did you know?Astronomers use “nutation” for Earth’s roughly 18.6-year axial cycle, largely driven by the Moon’s changing gravitational pull.
Etymological Timeline
Proto-Indo-European
PIE
*neu-
“To nod, bend, or incline; a reconstructed root associated with downward movement of the head.”
Ancient Greek
Greek
νεύειν (neúein)
“To nod or signal by inclining the head.”
Classical Latin
Latin
nuere
“To nod or give assent with a movement of the head.”
Classical Latin
Latin
nutare
“To nod repeatedly, sway, or oscillate; a frequentative form related to nuere.”
17th Century
English
nutation
“A nodding or oscillating motion, adopted from Latin for physical and astronomical movement.”
Modern English
English
nutation
“A periodic wobble or small oscillation superimposed on the rotation or precession of a body.”