The Spanish verb 'esfumar' (meaning 'to blur or fade') comes from the Italian word 'sfumare' meaning 'to fade away or dissipate'. The Italian term was formed by combining the prefix 's-' (meaning 'out' or 'away', derived from Latin 'ex-') with the word 'fumo' meaning 'smoke', which itself comes from Latin 'fumus' (smoke). The evolution of meaning from 'smoke' to 'fade/blur' makes intuitive sense, as smoke tends to blur objects and gradually fade away.

Some related Spanish words include 'humo' (smoke), 'fumar' (to smoke), and 'perfume' (perfume). All these words share the same Latin root 'fumus' meaning smoke. While 'esfumar' took on the metaphorical meaning of fading or blurring like smoke dissipating, these related words maintained more direct connections to the original concept of smoke or pleasant-smelling smoke (in the case of 'perfume').

English speakers might recognize the connection to words like 'fume', 'fumigation', and 'perfume', all of which derive from the same Latin root 'fumus'. While 'esfumar' developed to mean 'fade or blur', these English cognates maintained meanings more closely related to smoke, vapors, or gases. The word 'perfume' literally meant 'through smoke', referring to the ancient practice of creating pleasant scents by burning aromatic substances.