An Etymological Dictionary of Astronomy and Astrophysics

To set aside, e.g. → ignorable coordinate.

Etymology (EN): From Fr. ignorer, from L. ignorare “not to know, disregard,” from ignarus “not knowing, unaware,” from in- “not,”
→ un-, + gnarus “aware, acquainted with,” related to gnoscere “to → know”.

Etymology (PE): Nâdidé engâštan literally “supposed not seen,” from nâdidé “not seen” (from nâ- “not,” → un- + didé “seen,” p.p. of didan “to see,” → sight) + engâštan “to suppose” (→ hypothesis).