Final answer:
Ethnicity is the category that is not a racial category but instead encompasses shared cultural and linguistic heritage.
Step-by-step explanation:
The category that is NOT a racial category but instead an ethnic-language category is ethnicity. Race generally refers to physical characteristics that societies consider important, whereas ethnicity is based on shared culture that can include language, religion, and traditions. The U.S. government often categorizes people into 'Hispanic' or 'Not Hispanic', which revolves around language and is considered an ethnic categorization rather than racial. Hence, 'Race', 'Nationality', and 'Culture' are not correct as they do not primarily denote an ethnic-language category.