- semimajor axis
- noun Date: 1818 one half of the major axis of an ellipse (as that formed by the orbit of a planet)

*New Collegiate Dictionary.
2001.*

- semimajor axis
- noun Date: 1818 one half of the major axis of an ellipse (as that formed by the orbit of a planet)

*New Collegiate Dictionary.
2001.*

**semimajor axis**— [sem′imā′jər] n. Astron. one half of the longer axis of an elliptical orbit … English World dictionary**semimajor axis**— noun one half the major axis of an ellipse; the distance from the center of an ellipse to one end • Hypernyms: ↑axis • Part Holonyms: ↑major axis … Useful english dictionary**semimajor axis**— /sem ee may jeuhr, sem uy , sem ee , sem uy / 1. Geom. one half the major axis of an ellipse. 2. Astron. one half the major axis of the ellipse that one celestial body describes around another, as a planet around the sun or a satellite around a… … Universalium**semimajor axis**— sem′i•ma′jor ax′is [[t]ˈsɛm iˈmeɪ dʒər, ˈsɛm aɪ , ˌsɛm i , ˌsɛm aɪ [/t]] n. 1) math. one half the major axis of an ellipse 2) astron. one half the major axis of the ellipse that one celestial body describes around another, equivalent to the mean… … From formal English to slang**semimajor axis**— noun a) Half of the major axis of a circle or ellipse. b) Half of the distances between the two branches of a hyperbola … Wiktionary**semimajor**— adjective a) Of or pertaining to the semimajor axis, the long axis of an ellipse a semimajor radius b) Less than major, but still significant See Also: semiminor … Wiktionary**Semi-major axis**— The semi major axis of an ellipse The major axis of an ellipse is its longest diameter, a line that runs through the centre and both foci, its ends being at the widest points of the shape. The semi major axis is one half of the major axis, and… … Wikipedia**major axis**— noun the longest axis of an ellipse or ellipsoid; passes through the two foci (Freq. 7) • Hypernyms: ↑axis • Part Meronyms: ↑semimajor axis … Useful english dictionary**geoid**— geoidal, adj. /jee oyd/, n. 1. an imaginary surface that coincides with mean sea level in the ocean and its extension through the continents. 2. the geometric figure formed by this surface, an ellipsoid flattened at the poles. [1880 85; < Gk… … Universalium**celestial mechanics**— the branch of astronomy that deals with the application of the laws of dynamics and Newton s law of gravitation to the motions of heavenly bodies. [1815 25] * * * Branch of astronomy that deals with the mathematical theory of the motions of… … Universalium