prettygoodword | llama / guanaco / vicuña (but not alpaca)

llama (LAH-muh) - n., a domesticated South American camelid (Lama glama) raised as a pack animal and for its wool.

guanaco (gwah-NAH-koh) - n., a wild South American camelid (Lama guanicoe) of open areas of the Andes sought after for its wool.

vicuña or vicuna (vai-KOO-nyuh, vi-KOO-nuh) - n., a wild South American camelid (Lama vicugna) of upland areas of the Andes sought after for its wool.

The genetics is very complicated, but basically, llamas are domesticated guanacos with a little vicuña cross-breeding, while alpacas are domesticated vicuñas with a little guanaco cross-breeding -- notably, vicuñas and alpacas are more gracile than guanacos and llamas. All three names are (via Spanish) from the Classical Quechua names for them, llama, wanaku, and wik'uña. This one's a llama:

Thanks, WikiMedia!

As to why alpaca (al-PAK-uh), a domesticated South American camelid (Lama pacos) raised for its wool, is a bonus and not a main entry, that's because its name is not from Quechua, but Aymara, the unrelated dominant language of the Andes of northern Bolivia, with about 1.7 million speakers today. (Aymara won't be getting a theme week, because that's basically the only word we've gotten from it.)

---L.