A hollow area within the body: a sinus cavity. (noun)
A pitted area in a tooth caused by caries.(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.
Use "cavity" in a sentence
"Pour the still clear soap into your mold until the cavity is about 2/3 of the way full"
"This cavity is a real help to extract the victim and also provides 150 Liters of air to breath if you are buried."
"But police had been searching the backyard where they found what they call a cavity, where they believe human remains had been found and had been burned even."