The Spanish verb 'fumar' (to smoke) comes directly from the Latin verb 'fumare', which also meant 'to smoke'. The Latin verb 'fumare' was formed by combining the noun 'fumus' (meaning 'smoke') with the verbal suffix '-are', which was used to create verbs in Latin. This formation pattern of creating verbs from nouns was common in Latin, and the word has maintained both its form and meaning quite consistently as it evolved from Latin to Spanish.

Several common Spanish words are related to 'fumar' through the Latin root 'fumus'. These include 'humo' (smoke), 'humear' (to emit smoke), and 'perfume' (perfume). The initial 'f-' in Latin often changed to 'h-' in Spanish, which explains why 'humo' begins with 'h' while 'fumar' retained its 'f'.

English speakers can connect 'fumar' to several familiar English words that come from the same Latin root 'fumus'. These include 'fume' (as in 'fumes' or 'to fume with anger'), 'fumigation' (the act of applying smoke or fumes to disinfect), and 'perfume' (which originally referred to the smoke of burning incense). The connection between smoke and these modern English words helps illustrate how the ancient meaning has carried through to various related concepts.