blue blood
Preserved but no longer current.
High or noble birth or descent; it is a Spanish phrase, and refers to the fact that the veins shown in the skin of the pure- blooded Spanish aristocrat, whose race had suffered no Moorish or other admixture, were more blue than those of persons of mixed, and therefore inferior, ancestry.
Era: ca. 1898 (Victorian)
Sources & notes
Reproduced from Brewer’s Dictionary of Phrase and Fable (1898 edition, public domain; archive.org, retrieved 2026-07-31; OCR text, minor errors possible). Reflects the scholarship and attitudes of its era.
Common questions
What does “blue blood” mean?
High or noble birth or descent; it is a Spanish phrase, and refers to the fact that the veins shown in the skin of the pure- blooded Spanish aristocrat, whose race had suffered no Moorish or other admixture, were more blue than those of persons of mixed, and therefore inferior, ancestry.
Is “blue blood” formal or informal?
No register label has been reviewed yet — treat it as neutral and check the usage notes above.