noun
Etymology: translation of Spanish sangre azul
1. : the blood of noble, aristocratic, or socially prominent families
2.
a. : a member of a noble, aristocratic, or socially prominent family
a blue blood … related to half the noble families in the British isles — Time
b. : the nobility or aristocracy : the upper classes
one of high rank and birth, of the blue blood — Maria Edgeworth
• blue-blood·ed ˈ ̷ ̷| ̷ ̷ ̷ ̷ adjective