noun [U] a state of total confusion and lack of order
Snow and ice have caused chaos on the roads.
We muddled up the name labels and chaos ensued.
We had ten children at the party and chaos reigned all afternoon.
Ever since our secretary walked out, the office has been in (a state of) total/utter chaos.
Chaos theory is a scientific theory about situations that obey particular laws but appear to have little or no order.
The speaker told us that chaos theory says two things, that complex systems like weather have an underlying order and that simple systems can produce complex behaviour.
A frequent metaphor for one aspect of chaos theory is called the Butterfly Effect - butterflies flapping their wings in the Amazon affect the weather in Chicago.
chaotic
adjective The house is a bit chaotic at the moment - we've got all these extra people staying and we're still decorating.
He's a chaotic sort of a person - always trying to do twenty things at once.
chaotically
adverb