Merriam-Webster Collegiate Dictionary - generative nucleus

 noun  Date: circa 1892 the one of the two nuclei resulting from the first division in the pollen grain of a seed plant that gives rise to sperm nuclei — compare tube nucleus GENERATIVE SEMANTICS  noun plural but usually singular in construction  Date: 1970 a description of a language emphasizing a semantic deep structure that is logical in form, that provides syntactic structure, and that is related to surface structure by transformations