1. of or relating to the crissum (the region around the cloaca in birds, or the undertail coverts)
Usage: ornithology; technical

Examples

• The crissal feathers of the warbler displayed distinctive markings.
• Ornithologists examined the crissal region to identify the bird species.
• The crissal coverts are important features in bird classification.
• A crissal thrasher is named for the prominent crissal feathers on its underparts.