Sud vs. meridione vs. mezzogiorno

The Italian language has three main words for 'south': 'sud', 'meridione', and 'mezzogiorno'. While they all refer to the southern direction or region, they have subtle differences in usage and connotation.

Sud

'Sud' is the most basic and neutral term for south. It is used in general contexts and for geographic directions.
Il treno va verso sud.
(The train is heading south.)
Il vento soffia da sud.
(The wind is blowing from the south.)

Meridione

'Meridione' is a more formal or literary term for the southern part of a country, particularly Italy. It often implies a cultural or historical perspective.
Il meridione d'Italia ha una ricca storia.
(The south of Italy has a rich history.)
Le tradizioni del meridione sono diverse da quelle del nord.
(The traditions of the south are different from those of the north.)

Mezzogiorno

'Mezzogiorno' literally means 'midday' but is also used to refer to the south, particularly Southern Italy. It has cultural and socio-economic connotations.
Il problema del Mezzogiorno è un tema politico importante.
(The Southern Italy issue is an important political topic.)
Molti emigranti venivano dal Mezzogiorno.
(Many emigrants came from Southern Italy.)

Summary

While 'sud' is the most general term for south, 'meridione' is more formal and often used in cultural contexts, and 'mezzogiorno' specifically refers to Southern Italy with socio-economic implications. The choice between these words depends on the context and the specific aspect of 'south' being discussed.