big bang
Concise Oxford English Dictionary © 2008 Oxford University Press:
big bang
▶noun
- 1 Astronomy the rapid expansion of matter from a state of extremely high density and temperature which according to current cosmological theories marked the origin of the universe.
- 2 (Big Bang) (in the UK) the introduction in 1986 of major changes in trading in the Stock Exchange.
'big bang' also found in these Oxford entries:

