Also found in: Medical, Encyclopedia, Wikipedia.


A longitudinal fold of the intestinal wall in certain invertebrates that increases the absorptive and digestive surface area of the intestine.

[Greek tuphlos, blind + Greek sōlēn, pipe.]
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.


(in certain animals such as molluscs, annelids, and ascidians) a fold in the intestine or inner wall of the intestine
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014
References in periodicals archive ?
The mucosa of the style sac has an obscure typhlosole (i.e., internal fold) with a central intestinal groove (Fig.
By the absence of typhlosole and penial setae and by the presence of free lamellae in the esophagus of 11 and 12, P.
Only one epithelial fold (consisting of columnar epithelial cells with microvilli), known as the typhlosole, is present, where an abundance of larval connective tissue is located.