sphenoid sinus
noun
variants
or sphenoidal sinus
: either of two irregular cavities in the body of the sphenoid bone that communicate with the nasal cavities
Cite this Entry
“Sphenoid sinus.” Merriam-Webster.com Medical Dictionary, Merriam-Webster, https://www.merriam-webster.com/medical/sphenoid%20sinus. Accessed 31 Oct. 2025.
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