Also in Italian. "Mezzogiorno" both means noon and south.
Is it French (midi)?
South in French is sud, while noon is indeed midi. However, the two words are the same in Latin (meridies, lit. midday, as in p.m. = post meridiem, etc.), so probably in some of the other Romance languages they do match?
The south of France is known colloquially as "Le Midi".
Midi is also a word for south in French, colloquially.