[ad. L. ēvectiōn-em, n. of action f. ēvehĕre to carry out, f. ē- out + vehĕre to carry.]
† 1. A lifting up; elevation, exaltation (in quot. fig.). Obs. rare1.
1656. in Blount, Glossogr.
1659. Pearson, Creed, 513. His [Josephs] evection to the power of Egypt next to Pharaoh.
2. Astron. a. An inequality in the moons longitude (see quot. 1787).
1706. Phillips (ed. Kersey), Evection, or Libration of the Moon [The explanation confuses a and b.]
1787. Bonnycastle, Astron., 422. Evection, an inequality in the motion of the moon, by which, at her quarters, her mean place differs from her true one by about 21/2 degrees more than at her conjunction and opposition.
1834. Nat. Philos., Hist. Astron., ix. 45/1 (Usef. Knowl. Soc.). The evection discovered by Ptolemy is greatest in the quadratures.
1847. Whewell, Hist. Induct. Sc., I. 229. Such is the announcement of the celebrated discovery of the moons second inequality afterwards called by Bulhialdus evection.
1879. Newcomb & Holden, Astron., 163. The disturbing action of the sun [upon the moon] produces a great number of other inequalities, of which the largest are the evection and the variation.
† b. Alleged to have been used for LIBRATION.
1706. [see a].
1796. Hutton, Math. Dict., I. 450/1. Evection, is used by some astronomers for the Libration of the moon.
† 3. Evection of heat: the diffusion of heated particles through a fluid in the process of heating it: convection. Obs.