1. heliac - Noun
2. heliac - Adjective
Heliacal.
Source: Webster's dictionarythe heliacal rising of the Dog Star Source: Internet
the heliacal or Sothic year is determined by the heliacal rising of Sothis (the Egyptian name for the Dog Star) Source: Internet
Stellarators were developed by Lyman Spitzer in 1950 and have four designs: Torsatron, Heliotron, Heliac and Helias. Source: Internet