heli

a. [ Gr. &unr_; belonging to the sun, fr. &unr_; the sun: cf. F. héliaque. ] (Astron.) 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. Sir T. Browne. [ 1913 Webster ]

☞ The heliacal rising of a star is when, after being in conjunction with the sun, and invisible, it emerges from the light so as to be visible in the morning before sunrising. On the contrary, the heliacal setting of a star is when the sun approaches conjunction so near as to render the star invisible. [ 1913 Webster ]

adv. In a heliacal manner. De Quincey. [ 1913 Webster ]

n. [ Prob. fr. L. helianthes, or NL. helianthus, sunflower, in allusion to its color. ] (Chem.) An artificial, orange dyestuff, analogous to tropaolin, and like it used as an indicator in alkalimetry; -- called also methyl orange. [ 1913 Webster ]

a. (Zool.) Of or pertaining to the Helianthoidea. [ 1913 Webster ]

‖n. pl. [ NL., fr. L. helianthes sunflower + -oid. ] (Zool.) An order of Anthozoa; the Actinaria. [ 1913 Webster ]

n. any plant of the genus Helianthus having large flower heads with dark disk florets and showy yellow rays.
Syn. -- sunflower. [ WordNet 1.5 ]

a. [ From Helix. ] Of or pertaining to, or in the form of, a helix; spiral; as, a helical staircase; a helical spring. -- Hel"i*cal*ly, adv. [1913 Webster]

‖n. [ L., the marigold, fr. Gr. &unr_; a kind of plant. ] (Bot.) A genus of composite plants, with shining, commonly white or yellow, or sometimes reddish, radiated involucres, which are often called “everlasting flowers.” [ 1913 Webster ]