acronychal, acronycal, a.
(əˈkrɒnɪkəl)
Also acronical, achronical, achronycal, acronichal.
[f. prec. + -al1. Incorrectly spelt achronical, as if derived from χρόνος time; and with many intermediate forms.]
Happening in the evening or at night-fall, vespertine, as the acronychal rising or setting of a star. (Sometimes used as if = Rising in the evening or at sunset and setting at sunrise; but this is not correct. When the rising is acronychal, the setting is cosmical, and vice versâ.)
| 1594 Blundeville Exerc. iv. 35 (ed. 7) 492 Now to know the Acronical rising of any star at any time, bring the starre to the East part of the Horizon. 1622 Heylin Cosmogr. iii. (1682) 109 The rising and setting of the Stars, whether Heliacal, Acronical, Matutine, or Vespertine. 1642 More Poems (1647) 173 At eventide when they rise Acronicall. 1697 Dryden Virgil (1806) II. 159 The achronical rising..is when it appears at the close of day. 1751 Chambers Cycl. s.v., The Achronychal is one of the three poetical risings, and settings of the stars; and stands distinguished from Cosmical and Heliacal. 1837 Whewell Hist. Induct. Sci. (1857) I. 160 The acronycal and heliacal risings and settings of the stars. 1856 Burritt Astron. 60 [Incorrect use.] When a star rose at sun-setting, or set at sun-rising, it was called the Achronical rising or setting. |