\A*cron"yc\, Acronychal \A*cron"ych*al\, a. [Gr.
'akro`nychos at nightfall; 'a`kros + ny`x night.] (Astron.)
Rising at sunset and setting at sunrise, as a star; --
opposed to {cosmical}.
Note: The word is sometimes incorrectly written acronical,
      achronychal, acronichal, and acronical.