D defs.my
Entry 1 sense Webster, 1913

Heliacal

· He·li·a·cal · IPA /hɪˈlaɪ.ə.kəl/
01 a. Emerging from the light of the sun, or passing into it; rising or setting at the same, or nearly the same, time as the sun.
  1. 1.
    Emerging from the light of the sun, or passing into it; rising or setting at the same, or nearly the same, time as the sun.(Astron.)