The displacement of an electron beam from its straight-line path by an electrostatic or electromagnetic field.

1. Shape change or reduction in diameter of a conduit, produced without fracturing the material.

2. Elastic movement or sinking of a loaded structural member, particularly of the mid-span of a beam.

1. Horizontal clockwise angle between the axis of the bore and the line of sighting.

2. The setting on the scale to compensate for deflection.

In oil well drilling, a change in the angle of a well bore.