When translated to English, the phrase "definicion de palabras" means "definition of words." "Definicion de palabras" is a Spanish phrase and can be translated to any other language.
The Spanish word "de" can translate to either "of" or "from" in English but "of" is the word that works best for this specific phrase. It is also considered a proper translation to English from Spanish by saying "words definition" if a speaker wants to shorten up the phrase a bit. Either phrases are considered proper in both the English and the Spanish languages. If one wanted to add the phrase "what is the," "lo que es lo" would be added to the beginning of the Spanish phrase.