The Spanish word 'candela' comes from the Latin word 'candēla' meaning 'candle'. The Latin word was formed by combining the verb 'candēre' meaning 'to glow or shine' with the instrumental suffix '-la'. This suffix was used to create nouns referring to tools or instruments, so 'candēla' literally meant 'something that glows' - perfectly describing a candle's function.

Some related Spanish words include 'candente' (white-hot, glowing), 'candelabro' (candlestick), and 'candelaria' (Candlemas). All these words share the same root relating to light and fire.

English speakers might recognize the connection to words like 'candle', which comes from the same Latin root. Other related English words include 'candid' (originally meaning 'white, pure, bright') and 'incandescent' (glowing with heat), both of which trace back to the Latin 'candēre' meaning 'to glow'.