pidgin language

Any of various trade jargons, contact languages, or lingua francas arising in ports and markets where people of different linguistic backgrounds meet for commercial and other purposes. Usually a pidgin language is a rough blend of the vocabulary of one (often dominant) language with the syntax or grammar of one or more other (often dependent) groups. Pidgin English in various parts of the world, français petit negre, and Bazaar Hindi or Hindustani are examples of pidgins that have served long-term purposes to the extent of being acquired by children as one of their everyday languages.

At this point they become creole languages.

Generally, a pidgin language comes into existence to answer short-term needs - for example, the Korean Bamboo English used during the Korean War. Unless there is a reason for extending the life of such a hybrid form (in the case of Korean Bamboo English combining elements of English, Korean, and Japanese), it will fade away when the need passes.