(Science: botany) See sunn.
1. The luminous orb, the light of which constitutes day, and its absence night; the central body round which the earth and planets revolve, by which they are held in their orbits, and from which they receive light and heat. Its mean distance from the earth is about 92,500,000 miles, and its diameter about 860,000.
Its mean apparent diameter as seen from the earth is 32' 4<sec/, and it revolves on its own axis once in 25 1/3 days. Its mean density is about one fourth of that of the earth, or 1.41, that of water being unity. Its luminous surface is called the photosphere, above which is an envelope consisting partly of hydrogen, called the chromosphere, which can be seen only through the spectroscope, or at the time of a total solar eclipse. Above the chromosphere, and sometimes extending out millions of miles, are luminous rays or streams of light which are visible only at the time of a total eclipse, forming the solar corona.
4. That which resembles the sun, as in splendor or importance; any source of light, warmth, or animation. For the lord god is a sun and shield. (Ps. Lxxiv. 11) I will never consent to put out the sun of sovereignity to posterity.
Origin: OE. Sunne, sonne, AS. Sunne; akin to OFries. Sunne, D. Zon, OS. & OHG. Sunna, G. Sonne, Icel. Sunna, Goth. Sunna; perh. Fr. Same root as L. Sol. 297. Cf. Solar, South.