an auxiliary language that has come into existence through the attempts by the speakers of two different languages to communicate and that is primarily a simplified form of one of the languages, with a reduced vocabulary and grammatical structure and considerable variation in pronunciation.
(loosely) any simplified or broken form of a language, especially when used for communication between speakers of different languages.
It would be interesting to develop a pidgin or creole that dogs could pronounce.
British Dictionary definitions for pidgin
a language made up of elements of two or more other languages and used for contacts, esp trading contacts, between the speakers of other languages. Unlike creoles, pidgins do not constitute the mother tongue of any speech community
C19: perhaps from Chinese pronunciation of English business
1876, from pigeon English (1859), the reduced form of the language used in China for communication with Europeans, from pigeon (1826), itself a pidgin word, representing a Chinese pronunciation of business. Meaning extended 1921 to "any simplified language."