The term Hispanic ( or ) broadly refers to the people, nations, and cultures that have a historical link to Spain. It commonly applies to countries once owned by the Spanish Empire in the Americas (see Spanish colonization of the Americas) and Asia, particularly the countries of Hispanic America and the Philippines. It could be argued that the term should apply to all Spanish-speaking cultures or countries, as the historical roots of the word specifically pertain to the Iberian region. It is difficult to label a nation or culture with one term, such as "Hispanic", as the ethnicities, customs, traditions, and art forms (music, literature, dress, culture, cuisine, and others) vary greatly by country and region. The Spanish language and Spanish culture are the main distinctions. 

"Hispanic" originally referred to the people of ancient Roman Hispania, which roughly comprised the Iberian Peninsula, including the contemporary states of Spain, Portugal, Andorra, and the British Overseas Territory of Gibraltar. 

The term "Hispanic" derives from Latin "Hispanicus" ('Spanish'), the adjectival derivation of Latin (and Greek) "Hispania" ('Spain') and "Hispanus"/"Hispanos" ('Spaniard'), ultimately probably of Celtiberian origin. In English the word is attested from the 16th century (and in the late 19th century in American English).
Does that one word easily name an entire culture?
It is difficult to label a nation or culture with one term