The Spanish word 'lindo' (meaning 'beautiful' or 'pretty') has an interesting evolution from the Latin word 'legitimus', meaning 'legal' or 'complete'. The transformation from meaning 'legal' to 'beautiful' occurred through several phonetic changes in Old Spanish, where 'legitimus' first became '*leitimo', then '*leidimo', '*leidmo', and '*lidmo', all maintaining the meaning 'legitimate'. The shift in meaning from 'legitimate' to 'beautiful' likely developed from the sense of something being 'proper' or 'well-formed' to something being 'perfect' or 'beautiful'.

This semantic evolution from 'legal/legitimate' to 'beautiful' shows how meanings can shift dramatically over time, especially when describing qualities that people view positively. Something that was originally 'legitimate' or 'proper' came to be associated with aesthetic beauty.

The Spanish word 'legítimo' (meaning 'legitimate' or 'lawful') is a cognate of 'lindo', though it followed a different evolutionary path. While 'lindo' underwent significant sound changes and a meaning shift towards beauty, 'legítimo' maintained both its original form and meaning from Latin 'legitimus'.

English speakers might recognize the connection to words like 'legitimate' and 'legitimacy', which come from the same Latin root 'legitimus'. While the English words maintained the original legal and proper meaning, the Spanish 'lindo' evolved to describe physical beauty instead.