The Spanish word 'nona' comes from the Latin word 'nona', which meant 'ninth hour' or simply 'ninth'. This Latin term itself derived from 'nonus' meaning 'ninth'. In ancient Roman timekeeping, the 'nona hora' (ninth hour) referred to the ninth hour of daylight, approximately 3:00 PM in modern time.

In Spanish, you might encounter related words like 'noveno' (ninth), which, while not directly from the same Latin word, shares the concept of 'ninth' in Spanish numbering. The word 'nona' is less commonly used in modern Spanish except in specific contexts like religious services or historical references.

While English doesn't have many direct cognates from Latin 'nona', we do use the term 'noon', which interestingly enough is related to this concept. Although 'noon' now refers to midday (12:00 PM), it originally came from the Latin 'nona hora' (ninth hour, 3:00 PM). Over time, church services traditionally held at the ninth hour were moved earlier in the day, and eventually 'noon' came to mean midday in English.