Here in the central Rio Grande Valley, I've often heard the word “matanza” used to describe a large party in the traditional Hispanic culture. Generally it involves one or more whole pigs, roasted in a pit.
This word has twice led me to surprises.
One day a few years ago I was getting my teeth cleaned. I happened to mention to the hygienist that I was from Socorro, and she replied that she had family there, and was planning to attend a matanza that weekend.
“With a pig, and everything?” I replied.
“White people know about the pig?”
This was my first surprise: that a Hispanic person didn't consider herself white. She certainly looked Anglo to me.
The second surprise took a while to reveal itself. There is an arroyo in Socorro County that drains a huge area, arising at the foothills of the Magdalena range twenty miles from the river. It passes on the south side of Socorro, and has often flooded badly. In former years it has killed more than one resident. Two years ago it ran again, and trashed a large area. On top of much flooding, it took out a power pole and left a goodly area of the county without power for days. Here is a view up the arroyo, looking at the I-25 and NM-1 bridges. The Magdalenas are visible in the background.
Early news reports referred to this arroyo as Brown Arroyo. However, as usual around these parts, there is an earlier name in Spanish: Arroyo de la Matanza.
Finally a bilingual friend of mine clued me in: matanza means “slaughter.” The party is called that because it centers on the slaughter of a pig. And the arroyo is called that because it is a killer.