Caverna is a Spanish word that translates to "cavern" in English. This term is used to describe a large, natural underground chamber, cave or hollow. However, there are several other synonymous words that can also be used to represent this geological formation. One common synonym of caverna is cueva, which has a similar meaning and is also used in Spanish. Other synonymous terms for caverna in English include grotto, cavern, den, abyss, chasm and tunnel. Overall, all these words can be used to describe the same geological feature, and their use depends on the context and the preference of the speaker or writer.