1. a mass or lump.
  2. a semisolid mass, as of coagulated blood.
  3. a small compact group of individuals: a clot of sightseers massed at the entrance.
  4. British Informal. blockhead, dolt, clod.
verb (used without object), clot·ted, clot·ting.
  1. to form into clots; coagulate.
verb (used with object), clot·ted, clot·ting.
  1. to cause to clot.
  2. to cover with clots: Carefully aimed snowballs clotted the house.
  3. to cause to become blocked or obscured: to clot the book's narrative with too many characters.

Origin of clot

before 1000; Middle English; Old English clott lump; cognate with Middle Dutch klotte, German Klotz block, log (cf. klutz)
Related formsde·clot, verb, de·clot·ted, de·clot·ting.non·clot·ting, adjectiveun·clot·ted, adjective Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

British Dictionary definitions for unclotted


  1. a soft thick lump or massa clot of blood
  2. British informal a stupid person; fool
verb clots, clotting or clotted
  1. to form or cause to form into a soft thick lump or lumps
Derived Formsclottish, adjective

Word Origin for clot

Old English clott, of Germanic origin; compare Middle Dutch klotte block, lump
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for unclotted



Old English clott "a round mass, lump," akin to Dutch kloot "ball," Danish klods "a block, lump," German Klotz "lump, block;" probably related to cleat and clod.



early 15c., from clot (n.). Of fluids from 1590s. Related: Clotted; clotting.

Online Etymology Dictionary, © 2010 Douglas Harper

unclotted in Medicine


  1. A soft, nonrigid, insoluble mass formed when blood or lymph gels.
  1. To coagulate.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

unclotted in Science


  1. A soft insoluble mass formed when blood or lymph gels. During blood clotting, white blood cells, red blood cells, platelets, and various clotting factors interact in a cascade of chemical reactions initiated by a wound. When a body tissue is injured, calcium ions and platelets act on prothrombin to produce the enzyme thrombin. Thrombin then catalyzes the conversion of the protein fibrinogen into fibrin, a fibrous protein that holds the clot together. An abnormal clot inside the blood vessels or the heart (a thrombus or an embolus) can obstruct blood flow.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.