The Spanish word 'longevo' meaning 'long-lived' comes from the Latin word 'longaevus', which had the same meaning. The Latin 'longaevus' was formed by combining two Latin words: 'longus' meaning 'long' and 'aevum' meaning 'time, age, or lifetime'. This compound literally meant 'having a long lifetime' or 'long-lived'.

Some simpler Spanish words related to 'longevo' include 'largo' (long) and 'edad' (age). While 'largo' evolved from a different Latin word than 'longus', it carries the same basic meaning of length. 'Edad' evolved from Latin 'aetas', which is related to 'aevum'.

Several English words share roots with 'longevo'. The word 'longevity' is a direct cousin, coming from the same Latin roots. The 'long' part is obvious in English, while the '-evity' part comes from the same Latin 'aevum'. We also see this root in words like 'medieval' (middle age) and 'primeval' (belonging to the first ages). The word 'age' itself is also distantly related to the 'aevum' part of 'longevo'.