Vertiges literally translates to "dizziness" or "vertigo". It's a beautiful word that Indila uses to describe both a physical sensation and a state of emotional turmoil.
In the song, she sings of "Les vertiges et le labeur" (The vertigo and the toil), linking the dizzying feeling of her love and subsequent loss to the hard life of the man she loves. This word perfectly captures the disorienting emotions that make her feel like she's "spinning in the void" (tourner dans le vide), the song's central theme.
This song tells a tragic love story from the perspective of a woman whose lover is gone. She describes him with so much love: he was a working-class man, a stonecutter with tanned skin and damaged hands, "Il taillait la pierre, fils d'ouvrier" (He cut stone, a worker's son). She defends him fiercely against people who judged or laughed at him, telling them they are shallow and don't understand real hard work or deep feelings.
He was her entire world, and his memory makes her feel like she's spinning in nothingness, "Tourner dans le vide" (Spinning in the void). The lyrics make it clear he's not just on a trip; she says since he left, she hasn't been able to get back up. She even hopes to see him again "là-bas dans l'au-delà" (over there in the afterlife), which tells us he has died. The song is a powerful declaration of love for a man who was looked down on by society, but was everything to her.