• Webster's Revised Unabridged Dictionary
    • Solstitial Happening at a solstice; esp. (with reference to the northern hemisphere), happening at the summer solstice, or midsummer. "Solstitial summer's heat."
    • Solstitial Of or pertaining to a solstice.
    • ***
Century Dictionary and Cyclopedia
    • solstitial Of or pertaining to a solstice: as, a solstitial point.
    • solstitial Happening at a solstice—especially, with reference to the northern hemisphere, at the summer solstice, or midsummer.
    • ***
Chambers's Twentieth Century Dictionary
    • adj Solstitial pertaining to, or happening at, a solstice, esp. at the north one
    • ***


Webster's Revised Unabridged Dictionary
L. solstitialis,: cf. F. solsticial,
Chambers's Twentieth Century Dictionary
Fr.,—L. solstitiumsol, the sun, sistĕre, to make to stand—stāre, to stand.


In literature:

Belonging to summer; the solstitial point whereby the sun's ascent above the equator is determined.
"The Sailor's Word-Book" by William Henry Smyth
The Solstitial Points, or Solstices, are points of the Ecliptic at a distance of 90 deg.
"Lectures in Navigation" by Ernest Gallaudet Draper
They will arrive at the next solstitial feast.
"A Struggle for Rome, v. 1" by Felix Dahn
The first was an equinoctial, the second a solstitial armilla.
"Encyclopaedia Britannica, 11th Edition, Volume 2, Slice 5" by Various
Now the townsmen are all out of doors on account of the solstitial holiday.
"The Complete Opera Book" by Gustav Kobbé