Meaning

noun a lump of material formed from the content of a liquid

verb change from a liquid to a thickened or solid state

verb cause to change from a liquid to a solid or thickened state

originFrom Middle English clot, clotte, from Old English clott, from Proto-West Germanic *klott (“lump”). Cognate with German Klotz (“block”). Doublet of clod and klutz.

Etymology from Wiktionary, CC BY-SA 3.0