Bible Encyclopedias
Heliacal

1911 Encyclopedia Britannica

relating to the sun (iiXcos), a term applied in the ancient astronomy to the first rising of a star which could be seen after it emerged from the rays of the sun, or the last setting that could be seen before it was lost from sight by proximity to the sun.

Bibliography Information
Chisholm, Hugh, General Editor. Entry for 'Heliacal'. 1911 Encyclopedia Britanica. https://www.studylight.org/​encyclopedias/​eng/​bri/​h/heliacal.html. 1910.