Que yo sepa, la traducción de duende al inglés es elf. En México, un duende o chaneque es un espíritu que tiene aspecto de niño y que hace travesuras.

A duende can be meant something like a fairy- or goblin-like mythological creature. In somewhere, it is also said like some traits similar to "goblins" and "kobolds". However, in Spanish and Portuguese, The word is often considered to be equal to the English word "sprite", or the Japanese word yōkai and is used as an umbrella term for any fairy-like being such as goblins, pixies and elves (plural) /elf (singular). When it is refererred to Spanish Art circle, especially in Spain, "duende" is a term often used to describe flamenco singers or dancers who have or transmit that untranslatable quality.

I wanna find whoever told me it meant (more or less) "to have soul" and pummel them. No wonder every time I said it to someone they looked at me like they had no idea what I was saying! LOL And here I thought "duende" was soooo poetic.... jajaja

Well, I don't know about Spanish (sorry), but in Portuguese 'duende' means Leprechaun. Also, using google translate I found out that in Spanish it means 'elf' so it's kinda related. :-)