Definition of "descension"

descension

/dɪˈsɛnʃən/

noun
countable and uncountable, plural descensions
1. (now rare) Descent; the act of descending.
  Quotations
  From a God to a Bull? a heavy descension. It was Jove's case.
  c. 1597 (date written), William Shakespeare, “The First Part of Henry the Fourth, […]”, in Mr. William Shakespeares Comedies, Histories, & Tragedies […] (First Folio), London: […] Isaac Iaggard, and Ed[ward] Blount, published 1623, [Act II, scene v]
2. (astronomy, obsolete) The descent below the horizon of a celestial body.
  Quotations
  For in regard of time (as we elsewhere declare) the stars do vary their longitudes, and consequently the times of their ascension and descension.
  1646, Sir Thomas Browne, Pseudodoxia Epidemica, VI.3