<p><strong>Noun:</strong></p><ul><li>Astronomy. Either of the two times a year when the sun is at its greatest distance from the celestial equator: about June 21, when the sun reaches its northernmost point on the celestial sphere, or about December 22, when it reaches its southernmost point. Compare summer solstice, winter solstice.</li><li>Either of the two points in the ecliptic farthest from the equator.</li><li>A furthest or culminating point; a turning point.</li></ul>