a. Forms: 4 estyv·all, 5–6 estiv·all, e·stivall, 6 æsti·val, 6– estival, æstival. [a. Fr. estival (16th c. in Littré), ad. L. æstīvāl-is a secondary adj. f. æstīv-us (see ÆSTIVE); said at first only of the (summer) solstice, afterwards used instead of æstīvus, as more analogous to vernālis, autumnālis, hiemālis. The spelling with æ after the Latin, is the more common in later times, especially in Nat. Hist. to which the word is chiefly restricted. The historical accentuation is e·stival (cf. fe·stival); but estī·val appears in 1590 and was adopted by Dr. Johnson, after anal. of autu·mnal; the initial vowel in this and the following words in Æst- is by many pronounced (ī-).]
1. Of or belonging to summer, or the summer solstice.
1386. Almanak of Year (1812), 49. Fro þe stacyon of þe son estyval to þe stacyon of þe son hyemal.
1430. Lydg., Chron. Troy, I. iii. Where halowed is the stondyng estiuall Of freshe Appollo, with his golden wayne.
1535. Stewart, Cron. Scotl., I. 89. Fra the coluyre to tropic estivall.
c. 1590. Greene, Poems (1861), 303. When in æstival Cancers gloomy bower The greater glory of the heavens doth shine.
1698. [R. Ferguson], View of Eccles., 106. The Estival or Brumal Temper of the Air.
1753. Chambers, Cycl. Supp., Æstival solstice, the time when the sun enters the æstival point.
1880. M. Collins, Th. in Gard., I. 235. You generally get true summer in August: this year it has been unusually æstival.
2. Appearing or produced in summer.
a. 1682. Sir T. Browne, Misc., 92 (R.). Beside vernal, estival, and autumnal, made of flowers, the ancients had also hyemal garlands.
1870. Hooker, Stud. Flora, 365, Leucojum æstivum; leaves hibernal, flowers æstival.
