1. the top of a bird’s head, especially the crown area above the eyes
Usage: ornithology
2. a cap-like structure or covering
Usage: biology; technical

Examples

• The robin’s pileum was a distinctive reddish-brown color.
• Ornithologists use pileum coloration to identify different bird species.
• The male cardinal’s bright red pileum contrasts with its black face mask.
• Field guides often describe the pileum pattern for bird identification.
• The sparrow’s pileum showed subtle streaking that helped distinguish the species.
• Researchers noted variations in pileum size among the population.