When people argue about the definition or meaning of a word. This usually starts in the middle of an argument and distracts from the main topic of the argument. Whether done intentionally or not depends on the people arguing.

When an argument deteriorates and its focus becomes one about word definitions rather than the main topic, a person will usually say "Oh, now we're just arguing semantics". Usually by this point, the arguement has become a waste of time because it has morphed into a bunch of bickering about irrelevant, unimportant details rather than the original main point.

If someone accuses you of arguing semantics, they're usually accusing you of intentionally avoiding the topic. In this case, the person may or may not be misusing the phrase in order to do so. If you're not actually arguing about word definitions, then they should accuse you of being nit-picky instead (as that would be more accurate) but to explain it to this degree becomes a bit nit-picky in and of itself and so for obvious reasons, this is the end.

Intelligence agency term for "psychological operation". A government or corporate-sponsored operation, usually taking the form of a "terrorist attack" or "crazed gunman on a spree", with the intent of panicking the public into demanding more police and laws inhibiting freedom. Psyops are usually carried out by drugging a civilian or group of civilians with aggression-promoting drugs, psyching them up, arming them, and sending them out to commit mayhem. Government-sponsored terrorism. See also blackshirts, conspiracy

A phrase commonly used as a rebuttal in arguments, with two common meanings:

1) The person using the phrase has been subjected to a statement or argument that they don't like, but can't argue against; or

2) The person using the phrase doesn't understand the argument, or objects to or doesn't understand the use of polysyllabic words.