nadir

Etymology

From Medieval Latin nadir, from Arabic نَظِير السَّمْت (naẓīr as-samt), composed of نَظِير (naẓīr, “counterpart, corresponding to”) and السَّمْت (as-samt, “the zenith”)

noun

1. The point of the celestial sphere, directly opposite the zenith; inferior pole of the horizon; point of the celestial sphere directly under the place of observation.
   […] when we are Nadyr to the Sunne, we have no ſhadow […] 1638, Sir Thomas Herbert, Some years travels into divers parts of Asia and Afrique
2. (figurative) The lowest point; time of greatest depression.
   […] the seventh century is the nadir of the human mind in Europe […] 1837, Henry Hallam, Introduction to the Literature of Europe in the Fifteenth, Sixteenth, and Seventeenth Centuries
   In this nadir of poetic repute, when the only verse that most people read from one year’s end to the next is what appears on greetings cards, it is well for us to stop and consider our poets. 1950, Elizabeth Janeway, edited by Helen Hull, The Writer’s Book
   The myth describes the dangerous moment of the nadir, the dead of winter, the moment when it is not known whether the world will be re-created and another cycle will bring on another spring. 1981, William Irwin Thompson, The Time Falling Bodies Take to Light: Mythology, Sexuality and the Origins of Culture, London: Rider/Hutchinson & Co., page 175
3. (astronomy) The axis of a projected conical shadow; the direction of the force of gravity at a location; down.
   The nadir of the sun is the axis of the shadow projected by the Earth.
4. (beekeeping, archaic) An empty box added beneath a full one in a beehive to give the colony more room to expand or store honey.

verb

1. (transitive, beekeeping) To extend (a beehive) by adding an empty box at the base.