pes·sa·ry (p?s??-r?)n. pl. pes·sa·ries 1. Any of various devices worn in the vagina to support or correct the position of the uterus or rectum.2. A contraceptive diaphragm.3. A medicated vaginal suppository.[Middle English pessarie, from Late Latin pess?rium, from pessus, pessum, from Greek pessos, oval-shaped stone, pessary.]American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.pessary (?p?s?r?) n, pl -ries1. (Medicine) a device for inserting into the vagina, either as a support for the uterus or (diaphragm pessary) to deliver a drug, such as a contraceptive2. (Pharmacology) a medicated vaginal suppository[C14: from Late Latin pess?rium, from Latin pessum, from Greek pessos plug]Collins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014pes?sa?ry (?p?s ? ri) n., pl. -ries. 1. a device worn in the vagina to support a displaced uterus. 2. a vaginal suppository. 3. diaphragm (def. 4). [1350?1400; Middle English pessarie