Primaveras literally translates to "springs" (the season). While it's a common word, its use in this song is quite unique and poetic.
In "Un Millón De Primaveras," the artist uses "primaveras" to represent years, specifically a million years. This metaphorical use of a season to denote a vast expanse of time is a beautiful and memorable way to express an enduring, almost eternal, love and devotion. It's not just about the season, but about the countless cycles of life and renewal that pass, emphasizing the depth of the singer's commitment.
This song is a hilarious, over-the-top declaration of undying love and a refusal to move on! The singer is basically saying, "You want me to forget you? Forget my love? Change the lyrics of my songs and take your name out?" He responds with a dramatic, "Sólo falta un millón de primaveras, unos cuantos siglos sólo de adorar" [Only a million springs are missing, a few centuries of adoring]. He's not going to bother you after that, promise!
He even uses a funny analogy: if a dog barks at a thief and you say the dog is crazy for barking at the wrong person, he tells you to "aguanta un poco, ten paciencia, no le des otra pedrada" [wait a bit, have patience, don't throw another stone at it]. It's a playful way of saying, "Just bear with my love for a little longer!" He'll only stop singing about you if it bothers you after a million springs. It's a very Mexican, very dramatic, and very funny way to say, "I'm not over you yet!"