also haemato-, before vowels hemat-, haemat-, word-forming element in scientific compounds meaning "blood," from Greek haimato-, combining form of haima (genitive haimatos) "blood" (see -emia). Compare hemo-.
word-forming element, from Greek -oma, with -o-, lengthened stem vowel + -ma, suffix forming neuter nouns and nouns that indicate result of verbal action (equivalent of Latin -men); especially taken in medical use as "morbid growth, tumor," based on sarcoma, carcinoma.
<a href="https://www.etymonline.com/word/hematoma">Etymology of hematoma by etymonline</a>
Harper, D. (n.d.). Etymology of hematoma. Online Etymology Dictionary. Retrieved $(datetime), from https://www.etymonline.com/word/hematoma