D defs.my
Entry 1 sense Webster, 1913

Astatic

· A·stat·ic · IPA
01 a. Having little or no tendency to take a fixed or definite position or direction: thus, a suspended magnetic needle, when rendered astatic, l…
  1. 1.
    Having little or no tendency to take a fixed or definite position or direction: thus, a suspended magnetic needle, when rendered astatic, loses its polarity, or tendency to point in a given direction.(Magnetism)
Phrases & compounds
Astatic pair — a pair of magnetic needles so mounted as to be nearly or quite astatic, as in some galvanometers.