An Etymological Dictionary of Astronomy and Astrophysics

The lessening in size of the orbit of a binary system composed of two compact objects (pulsars/black holes) due to loss of energy by the system, in particular through gravitational wave radiation. This loss will cause the two objects to approach closer to each other, the orbital period decreases and the binary companions will eventually merge.

Etymology (EN): → orbital; shrinkage, from shrink, from M.E. schrinken, O.E. scrincan, from P.Gmc. *skrenkanan (cf. M.Du. schrinken, Swed. skrynka “to shrink.”

Etymology (PE): Darhamkešidegi “shrinking, shriveling,” from state noun of < i>darhamkešidé, from darham- “together, in eachother, toward eachother” (For etymology of dar-, → in-; for etymology of ham-, → com-)

• kešidé “drawn, shrivelled, wrinkled,” from Mod./Mid.Pers. kešidan, kašidan “to draw, protract,
  trail, drag, carry,” dialectal Yaqnavi xaš “to draw,” Qomi xaš “streak, stria, mark,” Lori kerr “line;”
  Av. karš- “to draw; to plow,” karša- “furrow;” Proto-Iranian *kerš-/*xrah- “to draw, plow;” cf. Skt. kars-, kársati “to pull, drag, plow;”
  Gk. pelo, pelomai “to move, to bustle;” PIE base k^wels- “to plow;” madâri, → orbital.