What does blood mean?
Blood is the vital red fluid that flows through the arteries and veins of humans and other vertebrates, transporting oxygen from the lungs, nutrients from digestion, and hormones throughout the body while carrying away carbon dioxide and waste. Composed of plasma, red and white cells, and platelets, it also clots to heal wounds and defends against infection. Beyond its biological sense, blood carries rich figurative weight in English: it denotes family lineage ('blood relations'), violence and killing ('spilled blood'), and strong emotion ('hot-blooded', 'blood boiling'). The word appears constantly in medical, legal, and everyday contexts — blood tests, blood donors, blood pressure — making it one of English's most versatile nouns. Its connotations range from life and vitality to danger and death, reflecting its dual role as sustainer of life and marker of injury.
The red fluid circulating in the body of humans and other vertebrates, responsible for transporting oxygen and nutrients and removing waste.
"The surgeon transfused two units of blood during the operation."
Chiefly British: to give someone their first experience of a particular activity, especially hunting or sport.
"The manager blooded several young players in the final friendly of the season."
Mostly used in sporting contexts.
Rarely pluralised; 'bloods' appears mainly in specialist contexts (e.g., different types of blood) or historical references to aristocratic families.
"The laboratory compared samples of the two bloods under a microscope."
In medieval medicine, doctors believed illness came from an imbalance of four 'humours' — and blood was one of them, so patients were bled to restore health.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of blood
Blood comes from Middle English 'blod', from Old English 'blōd', which derives from Proto-Germanic '*blōþan'. This ancient Germanic root gave rise to cognates across related languages, including Dutch 'bloed', German 'Blut', and Old Norse 'blóð'. The Proto-Germanic word may ultimately trace back to the same Indo-European root as Greek 'haima' (blood), though scholars are not fully certain of this connection. The word has remained remarkably stable in form and meaning across more than a millennium of English.
Related word forms
How blood is actually used
As a verb, chiefly British informal: 'to blood' means to initiate someone into an activity. The figurative senses around anger ('blood boiling', 'bad blood') are common in both formal and casual speech.
Easily confused with blood
'Blud' is an informal British slang term for a friend or brother, whereas 'blood' is primarily the bodily fluid or means family descent.