1 verb (T)
1 START STH to start something, especially an official, public, or military activity that has been carefully planned: launch a campaign/appeal/inquiry: Police have launched a murder enquiry following the discovery of a woman's body. | launch an attack/assault/offensive: The press launched a vicious attack on the President.
2 PRODUCT to make a new product, book etc available for sale for the first time: It was a party to launch her new novel.
3 BOAT to put a boat or ship into the water
4 SKY/SPACE to send a weapon or spacecraft into the sky or into space: A test satellite was launched from Cape Canaveral.
5 launch yourself forwards/up/from etc to jump up and forwards into the air with a lot of energy
launch into sth phrasal verb (T) to suddenly start a description or story, or suddenly start criticizing something: The preacher launched into an attack on adultery. launch out phrasal verb (intransitive always + adv/prep) to start something new, especially something that involves risk (+ into): Dickson left his father's firm and launched out into business on his own. 2 noun (C)
1 an occasion at which a new product, book etc is made available or made known: the launch of our new hatchback
2 a large boat with a motor

Longman dictionary of contemporary English. 2004.