The Spanish word 'nopal', referring to the prickly pear cactus, comes from the Nahuatl (Aztec) word 'nopalli', meaning 'cactus pad'. The Nahuatl term 'nopalli' itself is a compound word formed from two elements: 'nochtli' meaning 'prickly pear fruit' and 'palli' meaning 'leaf or flat thing'. This etymology perfectly captures the physical characteristics of the plant, combining references to both its edible fruit and its distinctive flat, paddle-shaped leaves or pads.

Since 'nopal' comes from Nahuatl, an indigenous language of Mexico, there aren't many simpler or more common Spanish words that share its etymology. However, you might encounter related terms like 'nopalera' (a place where nopales grow) or 'nopalito' (the edible young pad of the nopal cactus), which are both derived from 'nopal'.

There aren't any common English words directly related to 'nopal' since it comes from Nahuatl. However, English has borrowed the word directly as 'nopal' when referring to this type of cactus, particularly in botanical contexts or in discussions of Mexican cuisine. The English word 'prickly pear' is a descriptive term for the same plant but has a different etymology.