pannus noun4 •A hanging flap of skin or other tissue, especially one covering the cornea (in trachoma) or cartilage (in rheumatoid arthritis). •A type of accessory cloud, looking like shreds either attached to, or separated from, the main cloud formation; mainly associated with nimbostratus, cumulus, and cumulonimbus. •A birthmark on the skin. •A tent for a wound. formspanni · pannuses