Definition of heliacal
: relating to or near the sun —used especially of the last setting of a star before and its first rising after invisibility due to conjunction with the sun
heliacallyplay \-k(ə-)lē\ adverb
Did You Know?
The word heliacal rose in the mid-16th century. Its source is the Greek word hēlios, meaning "sun." Helios is also the Sun god of ancient Greece. Heliacal often suggests a relationship between a star and the sun as they appear to the human eye in the sky, as in our example sentences. It's also used in reference to the ancient Egyptian year, which began on the date when Sirius (or the Dog Star) first appeared on the eastern horizon at sunrise. English speakers have referred to this year as the heliacal year or the Sothic year. (Sothic comes from Sōthōs, the Greek word for Sirius.)
Origin and Etymology of heliacal
Late Latin heliacus, from Greek hēliakos, from hēlios
First Known Use: 1545
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