What is the one-to-many relationship between a legal entity and a contract called?

The one-to-many relationship between a legal entity and a contract is called aggregation or association with a cardinality of 1..*.

In modeling terms (e.g., UML), this is an association where one entity (legal entity) is linked to many other entities (contracts).

Example: one legal entity can have multiple contracts, but each contract belongs to one legal entity.

Thus, this is a classic "one-to-many" relationship.