A great circle passing through the poles and solstitial points.
·noun One of two great circles intersecting at right angles in the poles of the equator. One of them...
Webster's Dictionary of the English Language
·adj Of or pertaining to a solstice. II. Solstitial ·adj Happening at a solstice; ·esp. (with refer...
The two points where the tropics meet the ecliptic, in longitude 90° and 270°. ...
The Sailor's Word-Book