Tambora refers to a type of drum, specifically a large, double-headed drum often used in merengue and other Caribbean music genres. It's a central instrument in the song's rhythm and cultural context.
In the lyrics, the sound of the tambora is used as a metaphor for the singer's racing heart when he sees the object of his affection: "me repica el corazón como suena la tambora" (my heart beats like the tambora sounds). This makes the word not just a musical instrument, but a symbol of passion and excitement.
Vicente García opens "La Tambora" with a blunt, physical request: "Dame agua" [Give me water], "tengo sed, de tu vientre quiero beber" [I'm thirsty, from your womb I want to drink]. It's thirst standing in for desire, stated plainly rather than dressed up in metaphor. The tambora drum becomes the song's real subject: he compares his own pulse to it, "cuando tu me miras, me repica el corazón" [when you look at me, my heart beats], and the hook keeps returning to "como suena la tambora" [like the sound of the tambora] until the drum and the heartbeat are the same sound.
The track leans hard into perico ripiao, the accordion-and-tambora style from the Dominican countryside, and García even names two of the musicians who make that sound: "como le suena a Chocolate y a Otoniel" [like it sounds to Chocolate and Otoniel], a real credit rather than a generic shoutout, since Otoniel Nicolás plays the percussion on the record itself. By the final chorus the wordplay has mostly given way to repetition: he's not describing the beat anymore, he's just chanting along with it, letting the tambora take the song over the way it's clearly taken him over.