he·​li·​a·​cal | \ hi-ˈlī-ə-kəl How to pronounce heliacal (audio) \

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

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Other Words from heliacal

heliacally \ hi-​ˈlī-​ə-​k(ə-​)lē How to pronounce heliacally (audio) \ 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.)

Examples of heliacal in a Sentence

Recent Examples on the Web

There are lots of celestial bodies, but the biggest is Sirius, the dog star, and the 20 days before and the 20 days after its heliacal rising are called the dog days. Heliacal. Kevin Fisher-paulson, SFChronicle.com, "Dog dish: a tell-all by Bandit the Pekingese," 10 July 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'heliacal.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

First Known Use of heliacal

1545, in the meaning defined above

History and Etymology for heliacal

Late Latin heliacus, from Greek hēliakos, from hēlios

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Time Traveler for heliacal

The first known use of heliacal was in 1545

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