Dizionario vs. vocabolario
In Italian, both dizionario and vocabolario can be translated as dictionary, but they are not always interchangeable. While dizionario is the more precise and common term for the reference work, vocabolario has a broader meaning that includes a person's personal lexicon.
Dizionario
A1This is the most common, formal, and technical term for a dictionary. It refers specifically to the reference book or digital resource that systematically lists words (usually in alphabetical order) and provides their definition, etymology, pronunciation, and other linguistic information. It is the standard term for any type of dictionary, from general to highly specialized.
Ho consultato il dizionario per trovare il significato di quella parola.
(I consulted the dictionary to find the meaning of that word.)
Mi serve un buon dizionario di sinonimi e contrari.
(I need a good dictionary of synonyms and antonyms.)
Il Grande Dizionario della Lingua Italiana è un'opera monumentale.
(The Great Dictionary of the Italian Language is a monumental work.)
Questo è un dizionario tecnico di ingegneria meccanica.
(This is a technical dictionary of mechanical engineering.)
Uso spesso il dizionario online per le traduzioni.
(I often use the online dictionary for translations.)
Vocabolario
A2This word has two main meanings. Firstly, it can be used as a synonym for dizionario, especially in informal or school contexts, often referring to a simpler, more basic or portable volume. Secondly, and more distinctly, it means vocabulary—the set of words known and used by a person or a group. This second meaning is exclusive to vocabolario and is its most important distinction from dizionario.
L'insegnante ha chiesto agli studenti di portare il vocabolario di italiano in classe.
(The teacher asked the students to bring the Italian dictionary to class.)
Per il viaggio ho comprato un piccolo vocabolario tascabile.
(For the trip, I bought a small pocket dictionary.)
Leggere molti libri aiuta ad arricchire il proprio vocabolario.
(Reading many books helps to enrich one's own vocabulary.)
Quella bambina ha un vocabolario molto esteso per la sua età.
(That little girl has a very extensive vocabulary for her age.)
Il suo vocabolario è pieno di termini scientifici.
(His vocabulary is full of scientific terms.)
Ti prego, usa un vocabolario più educato quando parli con me.
(Please, use a more polite vocabulary when you speak with me.)
Summary
The key difference is that dizionario refers exclusively to the reference work (the book or digital tool). Vocabolario can also refer to the book, especially a simpler one for school, but its more specific and common meaning is the set of words a person knows and uses. Therefore, while you can sometimes use vocabolario for a physical dictionary, dizionario is always the correct and more precise term. Conversely, you can only use vocabolario to describe a person's personal range of words.