heliacal (adj.)youdaoicibaDictYouDict[heliacal 词源字典]
"pertaining to the sun," c. 1600, with -al (1) and Greek heliakos "of the sun," from helios "sun" (see sol). The heliacal year is reckoned from the heliacal rising of Sirius; thus it also is known as the canicular year.[heliacal etymology, heliacal origin, 英语词源]