The Spanish word 'mesero' (meaning 'waiter') comes from combining the Spanish word 'mesa' (meaning 'table') with the occupational suffix '-ero'. The word 'mesa' itself derives from the Latin word 'mensa', which also meant 'table'. The suffix '-ero' is commonly added to nouns in Spanish to indicate a person who works with or is associated with that thing - in this case, someone who works with tables, i.e., a waiter.

The most obvious related Spanish word is 'mesa' (table), which is both simpler and more common than 'mesero'. Understanding this connection makes it easy to remember that a 'mesero' is literally someone who works with 'mesas' (tables).

While English 'mensa' (as in the high IQ society) comes from the same Latin root, it's not a commonly used word in English. However, the word 'mess' (as in 'mess hall' or 'dining mess') actually comes from the same Latin root 'mensa'. Originally, a 'mess' was a portion of food placed on a table, and later came to mean the place where people eat together. This connection between tables and dining has persisted in both languages, though the meanings have evolved differently.