heliacal vs heliac

heliacal and heliac both are adjectives.

Word	Noun	Adjective	Verb	Adverb
heliacal	No	Yes	No	No
heliac	No	Yes	No	No

As adjectives, heliacal and heliac are synonyms defined as:

heliacal and heliac: pertaining to or near the sun; especially the first rising of a star after and last setting before its invisibility owing to its conjunction with the sun

heliacal (adjective)	heliac (adjective)
pertaining to or near the sun; especially the first rising of a star after and last setting before its invisibility owing to its conjunction with the sun	pertaining to or near the sun; especially the first rising of a star after and last setting before its invisibility owing to its conjunction with the sun