equinoctial

alternative æquinoctial

1. not comparableastronomyOf or relating to the spring or autumnal equinox.

   an equinoctial gale or storm, i.e. one happening at or near the time of the equinox, in any part of the world

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   In the Assyrian Standard [...] we see the figure of an Archer above that of a galloping Bull, and in another Assyrian Standard, that of Sargon II., we find not only the Archer and the Bull, the two constellations which 4,000 b.c. marked the equinoctial colure, but we may also clearly trace a reference to the two constellations which at the same date marked the solstitial colure, namely, those of the Lion and the Water-man.

   1903, Emmeline M. Plunket, Ancient Calendars and Constellations, London: John Murray, page 44

   Synonyms: equinoctal, equinoxial

2. not comparableastronomyOf or relating to the celestial equator.

   Synonyms: equatorial

3. not comparableuncommonEquatorial: of or relating to the equator of the Earth.
4. not comparablebiologyOf flowers: that open and close at particular times of day.

plural equinoctials · alternative æquinoctial

1. The great circle midway between the celestial poles; the celestial equator.

   The scorching beams under the equinoctial, or extremity of cold within the circle Arctic, […] cannot avoid or expel this heat, fury, and rage of mortal men.

   1624, Democritus Junior [pseudonym; Robert Burton], The Anatomy of Melancholy: […], 2nd edition, Oxford, Oxfordshire: […] John Lichfield and James Short, for Henry Cripps, →OCLC, partition III, section 2, member 1, subsection ii

2. rareThe terrestrial equator.

   Nor is this vveather rare about the Æquinoctiall; by Mariners termed the Tornadoes: and tis ſo vncertaine, that novv you ſhall haue a quiet breath and gale, and ſuddenly an vnexpected violent guſt, and ſtorme, ſo fierce, that many times the ſhips vvill feele no helme.

   1634, T[homas] H[erbert], “An Itinerarie of Some Yeares Trauaile, through Diuers Parts of Asia and Afrike, with the Description of the Orientall Indies, and Some Iles Adjacent. Especially the Territories of the Now Persian Monarchie: Included betwixt Mesopotamia, Indus, and the Caspian Sea”, in A Relation of Some Yeares Trauaile, Begunne Anno 1626. into Afrique and the Greater Asia, […], London: […] William Stansby, and Jacob Bloome, →OCLC, page 5

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   O conſider my caſe, moſt blisfull Queen, […] Diſpell thoſe Clouds which hover 'twixt my King and his higheſt Counſell, […] that my great Law-making Court be forced to turn no more to polemicall Committees, […] but that they may come again to the old Parliamentary Rode, To the path of their Predeceſſours, to conſult of means how to ſweep away thoſe Cobwebs that hang in the Courts of Juſtice, and to make the Laws run in their right Channell; to retrench exceſſive fees, and finde remedies for the future, that the poor Client be not ſo peeled by his Lawyer, and made to ſuffer by ſuch monſtrous delays, that one may go from one Tropick to the other, and croſſe the Equinoctiall twenty times, before his ſute be done; […]

   1645, James Howell, “England’s Tears, for the Present Wars, which for the Nature of the Quarrel, the Quality of the Strength, the Diversity of Battels, Skirmishes, Encounters, and Sieges, (Happened in so Short a Compasse of Time) Cannot be Parallel’d in Any Precedent Age”, in ΔΕΝΔΡΟΛΟΓΊΑ [DENDROLOGIA]: Dodona’s Grove, or The Vocall Forrest. The Third Edition More Exact and Perfect than the Former; with the Addition of Two Other Tracts: viz. Englands Tears for the Present Wars. And The Pre-eminence of Parlements, 3rd edition, Cambridge: Printed by R. D. for Humphrey Moseley, and are to be sold at his shop at the Prince's Arms in S. Pauls Church-yard, →OCLC, page 189

3. An equinoctial gale.

   Heavy with storm the coast-lines grew, / And sharp the equinoctials blew

   1868, The Family Herald: A Domestic Magazine of Useful Information and Amusement, page 209