in Astronomy, is the difference between the places of any celestial object, as seen from the surface and from the centre of the earth at the same instant. See Astronomy.

PARALLAX is also used to denote the change of place in any object arising from viewing it obliquely with respect to another object. Thus, the minute hand of a watch is said to have a parallax when it is viewed obliquely; and the difference between the instants shown by it when viewed directly and obliquely is the quantity of parallax in time.