interfere

American Heritage® Dictionary of the English Language, Fourth Edition

1. v. To be or create a hindrance or obstacle: loud talking that interfered with the other patrons' conversations; assistance that only interfered.
2. v. Sports To perform an act of interference.
3. v. To intervene or intrude in the affairs of others; meddle.
4. v. To strike one hoof against the opposite hoof or leg while moving. Used of a horse.
5. v. Physics & Electronics To cause interference.

Century Dictionary and Cyclopedia

1. To take a part in the affairs of others; especially, to intermeddle; act in such a way as to check or hamper the action of other persons or things.
2. To clash; come in collision; be in opposition: as, the claims of two nations may interfere; the two things interfere with each other.
3. In farriery, to strike one hoof or the shoe of one hoof against the fetlock of the opposite leg (of the same pair): said of a horse.
4. In physics, to act reciprocally upon one another so as to modify the effect of each, by augmenting, diminishing, or nullifying it: said of waves of light, heat, sound, water, etc. See interference, 5.
5. Synonyms Intermeddle, Intervene, etc. See interpose.
6. In base-ball, to obstruct unfairly a runner when he i s endeavoring to reach a base; also, so to obstruct a catcher or fielder who is endeavoring to handle or throw the ball.
7. In foot-ball, to interpose between a runner and would-be tacklers in order to assist the former.

Wiktionary

1. v. intransitive To get involved or involve oneself, causing disturbance.
2. v. intransitive, physics (of waves) To be correlated with each other when overlapped or superposed.

GNU Webster's 1913

1. v. To come in collision; to be in opposition; to clash; -- usually used with with.
2. v. To enter into, or take a part in, the concerns of others; to intermeddle; to interpose; -- used with in or with.
3. v. 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.
4. v. (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.
5. v. (Patent Law) To cover the same ground; to claim the same invention.

WordNet 3.0

1. v. get involved, so as to alter or hinder an action, or through force or threat of force
2. v. come between so as to be hindrance or obstacle