A more thorough explanation:

Definition: Quasi-affinity is a type of relationship that exists between two people, where one person is engaged to a relative of the other person. It is a civil law term that is similar to affinity.

Examples: If John is engaged to Mary, who is the sister of Jane, then John and Jane have a quasi-affinity relationship. Another example is if Sarah is engaged to Tom, who is the cousin of Jack, then Sarah and Jack have a quasi-affinity relationship.

Explanation: Quasi-affinity is a legal term that describes a relationship that is created by an engagement between two people. It is not a blood relationship, but it is still considered a type of affinity. The examples illustrate how two people can have a quasi-affinity relationship even if they are not related by blood or marriage.