obliquity

Etymology

From Middle French obliquité, from Latin obliquitas, from obliquus (“oblique”). Corresponding to oblique + -ity.

noun

1. The quality of being oblique in direction, deviating from the horizontal or vertical; or the angle created by such a deviation.
2. (astronomy, by extension, of a planet) Axial tilt.
   Calculating by spherical trigonometry, and assuming the same obliquity, I obtain 3 dundas and 40 pulas for the ascensional arc, giving a difference in time of 3 pulas, or about one of our minutes; an error so small, that even were the Indian astronomer aware of its existence he would disregard it, satisfied that the practical purposes which his labours subserve, are, notwithstanding, carried out with sufficient accuracy. 1839 October, J.J. Middleton, “Description of an Astronomical Instrument presented by Raja Ram Sing, of Khota, to the Government of India”, in Journal of the Asiatic Society, volume 8, number 94, page 837
3. Mental or moral deviation or perversity; immorality.
   Stray's [friends], apt to keep more to the shadows, tended to be practitioners of obliquity—as it quite often came down to, varieties of pimp. 2006, Thomas Pynchon, Against the Day, Vintage, published 2007, page 404
4. The quality of being obscure, oftentimes willfully, sometimes as an exercise in euphemism.