Definition of blood test:
(n) :
(medicine, hematology) A laboratory analysis performed on a blood sample that is usually extracted from a vein in the arm using a hypodermic needle, or by fingerprick.
(n) :
(law, genetics) An analysis of blood performed on two subjects to determine whether they are biologically related, such as a paternity test.
(v) :
(transitive, uncommon) To administer or conduct a blood test (on someone).