consanguinity

n. kinship, blood relation, connection through common ancestry

Consanguinity ("con- (with) (blood) -ity") refers to the property of being from the same genetic lineage as another person. In that respect, consanguinity is the quality of being descended from the same ancestor as another person. Consanguinity is an important legal concept in that the laws of many jurisdictions consider consanguinity as a factor in deciding whether two individuals may be married or whether a given person receives property when a deceased person does not leave a will.
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Consanguinity /con·san·guin·i·ty/ blood relationship; kinship.consanguin´eous con·san·guin·i·ty n. Relationship by blood or by a common ancestor. [more]Consanguinity - Community and Resources

Noun
1. related by blood
(synonym) blood kinship, cognation
(antonym) affinity, kinship by marriage
(hypernym) kinship, family relationship, relationship

(n.)
The relation of persons by blood, in distinction from affinity or relation by marriage; blood relationship; as, lineal consanguinity; collateral consanguinity.