A-crŏn'yc or A-crŏn'yc-al, a.

a. [Gr. ἀκρόνυκτος, ἀκρονύκτιος, from ἄκρος, extreme, and νύξ, night.] (Astron.) Rising at sunset and setting at sunrise, as a star;—opposed to cosmical. Hutton.

☞ The word is sometimes incorrectly written acronychal, achronycal, and acronichal.