Having relatively high resistance to flow.(adjective)
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 "viscous" in a sentence
"Grandbois: The last time I heard anything remotely flattering about Buckwaldo Mudthumper I was three feet deep in viscous sewage that had found its way into my garden apartment at the behest of one Mr. Juan Mandible Sick-Eyes and his uncompromising hoses."
"The baba ghanouj was actually tasty but overly pureed so it slid through my fork in viscous dribbles."
"As unappealing as such things are to me, it's more ... a fear of being choked, of drowing in viscous substances."