Definitions

1. adjective

relating to the sun’s apparent position at its greatest distance from the equator, or to the day of the year when this occurs (June 20/21 in the Northern Hemisphere and December 21/22 in the Southern Hemisphere)

“The solstitial alignment of the ancient temple was a testament to the advanced knowledge of the ancient civilization.”

2. noun

a solstice, especially the summer solstice

“The festival of lights marked the beginning of the solstitial season.”