efeito borboleta

== Portuguese == === Etymology === Compound of efeito (“effect”) +‎ borboleta (“butterfly”). Allusion that if a butterfly flapped its wings somewhere on Earth, this movement could change a system on the other side of the planet; popularly known for the allegory that the flapping of a butterfly's wings in Brazil could cause a tornado in Texas. === Pronunciation === === Noun === efeito borboleta m (usually uncountable, plural efeitos borboleta) butterfly effect (technical notion of sensitive dependence on initial conditions in chaos theory)