v. i. [ imp. & p. p. Interfered p. pr. & vb. n. Interfering. ] [ OF. entreferir to strike each other; entre between (L. inter) + OF. ferir to strike, F. férir, fr. L. ferire. See Ferula. ] [ 1913 Webster ]

1. To come in collision; to be in opposition; to clash; -- usually used with with; as, interfering claims, or commands; workers in a crowded shop may interfere with each other's activity. [ 1913 Webster +PJC ]

2. To enter into, or take a part in, the concerns of others; to intermeddle; to interpose; -- used with in or with; as, to interfere with the way I raise my children. [ 1913 Webster +PJC ]

To interfere with party disputes. Swift. [ 1913 Webster ]

There was no room for anyone to interfere with his own opinions. Bp. Warburton. [ 1913 Webster ]

3. To strike one foot against the opposite foot or ankle in using the legs; -- sometimes said of a human being, but usually of a horse; as, the horse interferes. [ 1913 Webster ]

4. (Physics) To act reciprocally, so as to augment, diminish, or otherwise affect one another; -- said of waves, rays of light, heat, etc. See Interference, 2. [ 1913 Webster ]

5. (Patent Law) To cover the same ground; to claim the same invention; as, to interfere with another patent. [ 1913 Webster ]

Syn. -- To interpose; intermeddle. See Interpose. [ 1913 Webster ]

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. One who interferes. [ 1913 Webster ]

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