‖ prosneusis Astron.
(prɒsˈnjuːsɪs)
[a. Gr. πρόσνευσις a nodding to, inclination towards; in Ptolemy as in sense a below; f. προσνεύειν to nod to, incline towards.]
In the Ptolemaic astronomy: a. prosneusis of the epicycle. A supposed deviation in the axis of the moon's epicycle, assumed as a correction to the lunar anomaly. b. The angle between the ecliptic and the great circle joining the centres of the moon and of the earth's shadow in a lunar eclipse.
| 1906 Dreyer Hist. Planetary Syst. ix. 196 The principle of rigorously uniform motion had been violated both by introducing a point outside the centre of the deferent, with regard to which the angular motion was uniform, and by the prosneusis. Ibid. xi. 252 He [Bertrand]..showed that Abu'l Wefa did not add his ‘mohazat’ to the prosneusis, the latter not being included in his ‘second anomaly’. 1908 ― Let. to Editor 20 Aug., [In reference to sense b] This is the prosneusis of the eclipsed part [of the moon]. |