Principal+point
111principal plane — Optics. a plane that is perpendicular to the axis of a lens, mirror, or other optical system and at which rays diverging from a focal point are deviated parallel to the axis or at which rays parallel to the axis are deviated to converge to a… …
112principal value — Math. a value selected at a point in the domain of a multiple valued function, chosen so that the function has a single value at the point. * * * …
113point\ out — v 1. To show by pointing with the finger; point to; make clear the location of. The guide pointed out the principal sights of the city. 2. To bring to notice; call to attention; explain. The policeman pointed out that the law forbids public sale… …
114principal value — Math. a value selected at a point in the domain of a multiple valued function, chosen so that the function has a single value at the point …
115principal focus — Optics. See focal point (def. 1). [1825 35] * * * …
116principal focus — /prɪnsəpəl ˈfoʊkəs/ (say prinsuhpuhl fohkuhs) noun → focal point (def. 1) …
117principal visual ray — noun : a perpendicular that extends from a station point to a perspective plane and theoretically passes precisely along the visual axis of a viewing eye …
118focal point — 1. Also called principal focus. Optics. either of two points on the axis of a mirror, lens, or other optical system, one point being such that rays diverging from it are deviated parallel to the axis upon refraction or reflection by the system… …
119main point — I noun backbone, basis, caput, cardinal feature, cardinal point, central idea, chief feature, chief issue, chief part, chief point, core, cream, critical feature, critical point, crucial feature, crucial point, crux, drift, elixir, essence,… …
120Accidental point — Accidental Ac ci*den tal, a. [Cf. F. accidentel, earlier accidental.] 1. Happening by chance, or unexpectedly; taking place not according to the usual course of things; casual; fortuitous; as, an accidental visit. [1913 Webster] 2. Nonessential;… …
