The Spanish word 'menos' meaning 'less' comes directly from the Latin word 'minus', which meant 'less' or 'smaller'. This is a straightforward inheritance where both the meaning and form have remained remarkably stable over time, with just a slight modification of the ending from '-us' to '-os' as the word evolved from Latin to Spanish.

Some common Spanish phrases using 'menos' include 'por lo menos' (at least), 'más o menos' (more or less), and 'al menos' (at least). These phrases are very common in everyday Spanish and show how this fundamental comparative word is used to express relative quantities or degrees.

English speakers might recognize the Latin root 'minus' in several common English words. The mathematical symbol '-' is called a 'minus' sign, directly preserving the Latin word. Other related English words include 'minimize' (to make smaller), 'minimum' (the least amount), and 'diminish' (to make less). The prefix 'mini-' as in 'miniskirt' or 'miniature' also comes from this same Latin root, all sharing the core meaning of 'smaller' or 'less'.