It means crack or crack in the beak. It is the name of a genus of birds belonging to the family Thamnophilidae. They are typical of South America and are known as battalions, sweet potatoes, anthills, tingling, tiluchí and fire-eye.
Rhegmatorhina : Genus of passerine birds of the family of tamnophilids native to South America and known by the common name of anthills.