n. [ See Interfere. ] [ 1913 Webster ]

1. The act or state of interfering; as, the stoppage of a machine by the interference of some of its parts; a meddlesome interference in the business of others. [ 1913 Webster ]

2. (Physics) The mutual influence, under certain conditions, as from streams of light, or pulsations of sound, or, generally, two waves or vibrations of any kind, producing certain characteristic phenomena, as colored fringes, dark bands, or darkness, in the case of light, silence or increased intensity in sounds; neutralization or superposition of waves generally. [ 1913 Webster ]

☞ The term is most commonly applied to light, and the undulatory theory of light affords the proper explanation of the phenomena which are considered to be produced by the superposition of waves, and are thus substantially identical in their origin with the phenomena of heat, sound, waves of water, and the like. [ 1913 Webster ]

3. (Patent Law) The act or state of interfering, or of claiming a right to the same invention. [ 1913 Webster ]

Interference figures (Optics), the figures observed when certain sections of crystallized bodies are viewed in converging polarized light; thus, a section of a uniaxial crystal, cut normal to the vertical axis, shows a series of concentric colored rings with a single black cross; -- so called because produced by the interference of luminous waves. --
Interference fringe. (Optics) See Fringe. [ 1913 Webster ]

n. a foreign policy of staying out of other countries' disputes; nonintervention.
Syn. -- nonintervention. [ WordNet 1.5 ]