The Spanish word 'latinidad' comes from the Latin word 'latinitas', which meant 'Latinity' or 'Latin character'. This Latin word was formed by combining 'latinus' (meaning 'Latin') with the suffix '-itas', which was used to create abstract nouns. When this word was borrowed into Spanish, the Latin suffix '-itas' naturally evolved into the Spanish form '-idad', following regular sound changes between the languages.

Many common Spanish words share this same pattern of deriving from Latin words with '-itas' becoming '-idad'. Some simpler examples include 'unidad' (unity), 'realidad' (reality), and 'actividad' (activity). The suffix '-idad' is very productive in Spanish and is used to form abstract nouns, similar to how English uses '-ity'.

The word 'latino' in Spanish is also obviously related, being a direct descendant of Latin 'latinus'. Today 'latinidad' often refers specifically to the shared cultural identity and characteristics of Latin American people.

English has many cognate words from the same Latin source. The most direct parallel is 'Latinity', which like Spanish 'latinidad' comes from Latin 'latinitas'. The word 'Latin' itself comes from 'latinus'. English also borrowed many words ending in '-ity' from Latin words that ended in '-itas', following the same pattern as 'Latinity': examples include 'unity', 'reality', and 'activity'.