Malincunia is the beautiful Neapolitan dialect version of the standard Italian word malinconia, which translates to melancholy or wistful sadness.
In this world-famous song, the singer describes the deep emotion that washes over him when the sun sets and night falls. He uses this highly poetic word to express how much he longs to stay right under his lover's window, perfectly capturing the passionate spirit of classic Italian romance.
Everyone loves a clear sky right after a storm. The song opens by celebrating that feeling: Che bella cosa na jurnata 'e sole ("What a lovely thing is a sunny day") and N'aria serena doppo na tempesta ("Calm air after a storm"). The fresh air feels like a party is starting. But Italian operatic-pop trio Il Volo quickly flip the script with an extreme compliment. Real sunlight is fine, sure, but there is a much better sun: 'O sole mio sta 'nfronte a te ("My sun shines from your face"). The singer literally tells their love that their forehead or face shines brighter than the actual star in our solar system. It is dramatic, cheesy, and completely charming.
Then things take a classic romantic turn once night falls. When daylight fades (Quanno fa notte e 'o sole se ne scenne / "When night comes and the sun goes down"), a wave of gloom arrives: Me vene quase 'na malincunia ("A sadness almost comes over me"). Instead of going home to sleep like a normal person, the singer wants to linger right outside: Sotto 'a fenesta toia restarria ("Under your window I would stay"). Why? Because losing the sky's sun does not matter as long as they can look up and catch sight of their favorite face again.