Real Dictionary

blow up
phrasal verb: If a wind or a storm blows up, the weather becomes very windy or stormy.
phrasal verb: If someone blows something up or if it blows up, it is destroyed by an explosion.
phrasal verb: If you blow up something such as a balloon or a tyre, you fill it with air.

blow up in American English
to come into being
to fill with or as with air or gas

blow up in British English
to explode or cause to explode
adjective: designed to be inflated by air or breath
noun: an explosion

blow-up
countable noun: A blow-up is a photograph or picture that has been made bigger.