equatorial
/ˌɛkwəˈtɔːɹiəl/ adjective, noun
Forms equatorials
- adjective (geography) Of, near, or relating to the equator. “That plant is best suited to equatorial climates.”
- adjective Relating to the midline of any approximately spherical object.
- adjective (organic chemistry) of a bond, lying approximately in the plane of a ring, perpendicular to its axis
- noun (astronomy) A kind of telescope mounted so as to have two axes of motion at right angles to each other, one of them parallel to the axis of the Earth, and each carrying a graduated circle, one for measuring declination, and the other right ascension, or the hour angle, so that the telescope may be directed, even in the daytime, to any star or other object whose right ascension and declination are known.
Antonyms
Etymology
Cf. F. équatorial.
Webster’s 1913
- adjective Of or pertaining to the equator; as, equatorial climates; also, pertaining to an equatorial instrument.
- noun An instrument consisting of a telescope so mounted as to have two axes of motion at right angles to each other, one of them parallel to the axis of the earth, and each carrying a graduated circle, the one for measuring declination, and the other right ascension, or the hour angle, so that the telescope may be directed, even in the daytime, to any star or other object whose right ascension and declination are known. The motion in right ascension is sometimes communicated by clockwork, so as to keep the object constantly in the field of the telescope. Called also an equatorial telescope.
Sources: Wiktionary · WordNet 3.0 · Webster’s 1913 — from the Wiktionary entry “equatorial”, CC BY-SA 4.0. Details