Dictionary.com
Thesaurus.com

hematoma vs. blood clot

[hee-ma-toh-muh, hem-uh-] / ˌhi mæˈtoʊ mə, ˌhɛm ə- /

noun

Pathology.

plural

hematomas, hematomata
  1. a circumscribed collection of blood, usually clotted, in a tissue or organ, caused by a break in a blood vessel.

[bluhd klot] / ˈblʌd ˌklɒt /

noun

  1. a mass of coagulated blood, as within a blood vessel or at the site of an open wound.