Definition of "sinusitis" [sinusitis]

• Inflammation of the sinuses or a sinus, especially in the nasal region. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "Short-term sinusitis can be caused by either a bacterial infection, which may respond to treatment with antibiotics, or a viral infection, which doesn't."
• "What typically happens is the chicken may develop sinusitis, which is just inflammation of the sinuses."
• "Rhinosinusitis, also called sinusitis, is an inflammation or swelling of the lining in the sinus cavities."