A javelina is a relative of the wild boar native to parts of Central and South America. The word was borrowed into English in the 1830s from the Spanish word jabalina (the b to v switch happened because most Spanish dialects use a bilabial fricative that sounds halfway between the letters). That's a diminutive of jabalí, which means "wild pig" in general and traces to an Arabic dialect in southern Spain. Ultimately, it's thought to derive from the word jabal, meaning "mountain", since javelinas were traditionally associated with mountains (and jabal is from the Proto-Semitic root j-b-l, with the same definition). Javelinas are also sometimes called "skunk pigs" or "peccaries" in the Americas; the latter name is from the Carib word pakira, with no further research telling us about its etymology.
Adam Aleksic, a rising sophomore studying linguistics and government at Harvard University, has been described as the internet's sixth most famous etymologist. He also has disturbing interests in politics, vexillology, geography, board games, conlanging, and law.