The definition of a cousin-german is a first cousin or the child of someone's aunt or uncle.
(noun)An example of a cousin-german is the child of your mother's brother.
See cousin-german in Webster's New World College Dictionary
noun pl. cousins-german
Origin: Fr cousin germain: see cousin & German
See cousin-german in American Heritage Dictionary 4
noun pl. cous·ins-ger·man (kŭzˌĭnz-)