Used in some classification systems

• A suborder or superfamily nearly coextensive with suborder Tyranni
• Passeriformes having relatively simple vocal organs and little power of song clamatorial birds

The Collaborative International Dictionary Word definitions in The Collaborative International Dictionary
Clamatores \Clam`a*to"res\, n. pl. [L. clamator, pl. clamatores, a bawler.] (Zo["o]l.) A division of passerine birds in which the vocal muscles are but little developed, so that they lack the power of singing.