An Etymological Dictionary of Astronomy and Astrophysics

1. Navigation: The angular difference between the visible horizon and the true horizon. Same as → dip of the horizon.
   

2. Geodesy: The angle between the horizontal and the lines of force of the Earth’s magnetic field at any point. → magnetic dip.
   

3. Aviation: The angle between the true and apparent horizon, which depends on flight height, the Earth’s curvature, and refraction.

Etymology (EN): O.E. dyppan “to immerse,” cognate with
Ger. taufen “to baptize,” and with → deep.

Etymology (PE): Našib, → depression.