The Spanish verb 'mear' (to urinate) comes from the Vulgar Latin 'meiare', which in turn derives from Classical Latin 'meio', both meaning 'to urinate'. This is a case where the word has maintained its original meaning throughout its evolution from Latin to modern Spanish, with only phonetic changes occurring over time. The Latin 'meio' evolved to 'meiare' in Vulgar Latin, and then simplified to 'mear' in Spanish through regular sound changes.

This is a basic verb that doesn't have many related simpler Spanish words. Its form has remained relatively unchanged since Latin times and represents a fundamental biological function.

While there aren't any commonly used English words directly related to 'mear', English borrowed medical and scientific terms from the same Latin root, such as 'micturition' (the medical term for urination). However, these are highly technical terms that entered English through scientific Latin rather than through natural language evolution.