live blood
/ˈlʌɪv blʌd/noun
1The blood of a living person or animal. Also: blood drawn directly from a person or animal when living or immediately after death, especially while it remains unclotted or contains living cells.
2Slight involuntary twitching of a muscle, especially of the eyelids; myokymia. Compare earlier lifeblood.
Origin
Early 17th century; earliest use found in Thomas Middleton (d. 1627), playwright. From live + blood, as an alteration of lifeblood.