8 letters · 13 points in Scrabble
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
originFrom Ancient Greek ἡλιακός (hēliakós, “of the sun”) + -al. Appears in English first in the 16th century.
Etymology from Wiktionary, CC BY-SA 3.0