SKIP TO CONTENT

libration

Definitions of libration
  1. noun
    (astronomy) a real or apparent slow oscillation of a moon or satellite
    “the libration of the moon”
    see moresee less
    type of:
    variation
    (astronomy) any perturbation of the mean motion or orbit of a planet or satellite (especially a perturbation of the earth's moon)
    oscillation
    the process of oscillating between states
Word Family
EDITOR’S CHOICE

Test prep from the experts

Boost your test score with programs developed by Vocabulary.com’s experts.

  • Proven methods: Learn faster, remember longer with our scientific approach.
  • Personalized plan: We customize your experience to maximize your learning.
  • Strategic studying: Focus on the words that are most crucial for success.

SAT/PSAT

$29.95
  • Number of words: 500+
  • Duration: 8 weeks or less
  • Time: 1 hour / week

TOEFL

$29.95
  • Number of words: 500+
  • Duration: 10 weeks or less
  • Time: 1 hour / week

ACT

$29.95
  • Number of words: 700+
  • Duration: 10 weeks
  • Time: 1 hour / week