Estéril literally translates to "sterile," a word you might know from a science class. It means barren or unable to produce life.
In this song, Tainy uses it in a powerful and surprising metaphor: "Tengo el corazón estéril" (I have a sterile heart). He's saying his heart is empty and unable to grow feelings or love, poignantly describing his loneliness despite having fame and money. This unique use of the word makes it incredibly memorable.
In "MOJABI GHOST," Puerto Rican producer Tainy and Bad Bunny team up for a track named after the luxury Byredo perfume Mojave Ghost. Bad Bunny fills his days with every distraction money can buy: Lamborghinis in Puerto Rico, Bugattis in Miami, partying on yachts, and heading home with two people at once ("Pa' mi cama nos vamos los tres" [The three of us are going to my bed]). He flexes like baseball superstar Shohei Ohtani ("Pichando y dando palos como Ohtani" [Pitching and hitting home runs like Ohtani]) and celebrates winning rings like basketball star Giannis Antetokounmpo. But none of the VIP lifestyle actually works as a distraction.
The real punch of the song hits when the party ends. As he puts it plainly: "Los millones no aguantan el llanto / De cuando me siento sólo en mi cuarto" [Millions can't hold back the tears / From when I feel alone in my room]. He admits that all the drinking, smoking, and partying is just a cover-up ("fingiendo / Que ya no pienso en ti" [pretending / that I don't think about you anymore]) because heartbreak keeps him wide awake at night. In fact, he straight-up confesses he would trade all the fame and wealth just to know what their kiss tastes like and get them out of his head for a single day.