'palfrey' originates from Old French, specifically the word 'palefroi' (also spelled 'palefrei'), which in turn came from Medieval Latin 'paraveredus', where the prefix 'para-' meant 'beside' and 'veredus' meant 'post horse'.

'palfrey' changed from the Old French word 'palefroi' (derived from Medieval Latin 'paraveredus') and entered Middle English as forms such as 'palfrei' before becoming the modern English word 'palfrey'.

Initially, it referred to a 'post horse' or spare horse used for couriering and travel, but over time it evolved into the meaning 'a gentle riding or saddle horse' used chiefly for comfortable riding.