D defs.my
Entry 4 senses Webster, 1913

Elongation

/ēlˌ-ông-gāsh'-ən/ · E·lon·ga·tion · IPA /ˌiːlɔŋɡˈeɪʃən/
01 n. The act of lengthening, or the state of being lengthened; protraction; extension.
  1. 1.
    The act of lengthening, or the state of being lengthened; protraction; extension.
  2. 2.
    That which lengthens out; continuation.
    “May not the mountains of Westmoreland and Cumberland be considered as elongations of these two chains?” — Pinkerton.
  3. 3.
    Removal to a distance; withdrawal; a being at a distance; distance.
    “The distant points in the celestial expanse appear to the eye in so small a degree of elongation from one another, as bears no proportion to what is real.” Glanvill.
  4. 4.
    The angular distance of a planet from the sun; as, the elongation of Venus or Mercury.(Astron.)