Oaxaca knife/sword (also "Oaxaqueño machete-sword" or, loosely, "Oaxaca Bowie"). Carved bone? (looks very much like ivory and some were made with it) with grooved/fluted handle. The eagle brass pommel cap is also a hallmark of the earliest manufactured. The engraved dicho (saying) is a traditional Mexican inscription about a man's wife and horse getting lost — this kind of engraved dicho, often paired with the eagle is standard on these blades.
These were made by regional Oaxaca smiths from the late 1800s into the mid-1900s — the best-documented maker family is Argón (Austreberto Argón and descendants, based in Oaxaca city), whose work is well known to collectors and turns up regularly in arms-and-armor forums. Blade shape (recurved, cleaver-like tip), full tang construction, and hand-cut/etched decoration (vs. stamped) are what separate an older/better example from a modern tourist reproduction.
This example is 20" and is in its original sheath. The only detraction is some pitting on the blade and some stitching missing on the bottom of the sheath.
**All edge tools may need to be sharpened and/or honed before use**
