Which term describes one who inherits the property of another by operation of law rather than by will?

The term that describes one who inherits the property of another by operation of law rather than by will is "heir." An heir is a person who is legally entitled to inherit some or all of the estate of another person when that person dies intestate, meaning without a valid will. Inheritance by operation of law occurs according to the laws of descent and distribution established by the state, which dictate who is eligible to inherit based on their relationship to the deceased. This ensures that property is passed down to relatives or beneficiaries as determined by statutory regulations rather than the specific wishes of the deceased, which would be outlined in a will.

The other terms do not apply to the scenario of inheritance. A guardian refers to a person appointed to manage the affairs or take care of a minor or an incapacitated individual. A lessor is someone who leases or rents property to another person, often in a contractual relationship. Lastly, a misdemeanor is a type of criminal offense that is less serious than a felony and has no relation to inheritance or property transfer. Therefore, "heir" is the appropriate term in the context of legal inheritance.