Ciprés translates to "cypress tree." While it might seem like a simple tree, the cypress holds significant cultural and symbolic weight in many Spanish-speaking countries, often associated with cemeteries and remembrance.
In the song, the lyric "Hoy regreso a dejar flores a la sombra de un ciprés" (Today I return to leave flowers in the shadow of a cypress) strongly suggests a visit to a grave. This word evokes a sense of loss, memory, and a past relationship that has ended, making it a poignant and memorable choice that hints at the song's melancholic theme.
"Diciembre" opens on a memory the singer can't quite put down: a name once carved "junto al mío en la pared" (next to mine on the wall), replaced now with flowers left in the shadow of a cypress, a tree that in Spanish is basically shorthand for a cemetery. That's the register for the whole song. It never raises its voice about the breakup, it just keeps circling small domestic details, like who paid for dinner or what it felt like to wake up on a Sunday, and asks "qué más da" (what does it matter) about each one while clearly still caring plenty.
The chorus asks the real question underneath all that shrugging: "¿Cómo puede ser que duela tanto?" (how can it hurt so much?), if there's really nothing left to talk about or hide. The title comes from the sharpest image in the song, near the end: "qué más da mirarnos si siempre es diciembre" (what does it matter if we look at each other, since it's always December). Time never actually moved on. It just stopped at the coldest point and stayed there, no matter how many real months have passed since it ended.