The Spanish word 'joven' meaning 'young' comes directly from the Latin word 'iuvenis', which referred to a young person, specifically someone between 30-45 years old in Roman society. Over time, as the word evolved from Latin to Spanish, the initial 'i' changed to 'j' (a common sound change in Spanish), and the meaning broadened to simply mean 'young' in general, rather than referring to a specific age range.

The Spanish word 'juventud' (youth) is closely related to 'joven', both coming from the same Latin root. Similarly, 'juvenil' (juvenile, youthful) maintains an even closer connection to the original Latin form.

Several English words share the same Latin ancestor as 'joven'. The word 'juvenile' comes directly from Latin 'iuvenilis' (derived from 'iuvenis'). Other related English words include 'rejuvenate' (to make young again), 'junior' (younger), and even 'young' itself, though this connection goes back to an even older Indo-European root.