1. An amber, watery fluid, rich in proteins, that separates out when blood coagulates
   "Blood serum is often used in laboratory tests to detect antibodies";
   - blood serum
    
2. A watery fluid from animal tissue, esp. from serous membranes
   "The scientists extracted serum from the blood samples for further analysis"

Derived forms: serums, sera

Type of: bodily fluid, body fluid, humor [US], humour [Brit, Cdn], liquid body substance

Part of: blood

Encyclopedia: Serum, India