The Spanish word 'dolor' (meaning 'pain') comes directly from the Latin noun 'dolor' (meaning 'pain, suffering'). The Latin 'dolor' was formed from the verb 'dolere' ('to suffer, feel pain') combined with the suffix '-or', which was used in Latin to form nouns indicating the result or effect of an action. So 'dolor' literally represented the result or state of suffering or feeling pain.

Several common Spanish words are related to 'dolor', including 'doler' (to hurt), 'doloroso' (painful), and 'doliente' (grieving, suffering). These all share the same Latin root 'dolere' and maintain the core meaning related to pain or suffering.

In English, we have several words that come from the same Latin root, including 'dolorous' (meaning full of sorrow), 'condolence' (expression of sympathy for someone's pain or grief), and 'indolent' (originally meaning 'free from pain' but now meaning 'lazy'). The medical term 'analgesic' often appears with 'dolor' in the Latin phrase 'sine dolor' meaning 'without pain'.