blood-serum
/blˈʌdsˈɛɹəm/
/blˈʌdsˈɛɹəm/
Etymology
Old EnglishLatinEnglish
This compound joins 'blood', from Old English, with 'serum', a Latin word for a watery liquid. It names the part of blood left after clotting, and medical writing often prefers the open form 'blood serum' over the hyphenated spelling.