Que onda is spelled "¿Qué onda?" and is slang in Spanish for "Whats up?"

This slang/greeting is mostly used in Mexico, Argentina, Uruguay, Guatemala and Chile.

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

whats up?

Spanish for "What's up".

A constellation of sixties hippie expressions which are still quite current. This is the standard hip youth greeting, as ubiquitous as "What's happening?"