Why Is It Called a “Solstice?" During a year, the subsolar point—the spot on the Earth's surface directly beneath the Sun—slowly moves along a north-south axis. Having reached its southernmost point at the December solstice, it stops and starts moving northward until it crosses the equator on the day of the March equinox. At the June solstice, which marks the northernmost point of its journey, it stops again to start its journey back toward the south.
This is how the solstices got their name: the term comes from the Latin words sol and sistere, meaning “Sun" and “to stand still".
Read more at https://www.timeanddate.com/calendar/june-solstice.html
