What is the legal term for unauthorized possession of someone else's property?

The correct response is based on the understanding that "conversion" is the legal term that refers to the unauthorized possession or control of someone else's property. This concept is widely recognized in tort law, where conversion occurs when an individual takes or uses someone else's property without permission, essentially treating it as their own. This act obstructs the true owner’s rights and can require the person who committed the conversion to compensate the owner for the value of the property or its possession.

In the context of this question, conversion is significant because it encompasses a range of actions that involve misappropriation and can apply to tangible items or personal property. For example, if someone borrows a neighbor's lawnmower and keeps it without the owner's consent, that person may be liable for conversion.

The other terms provided refer to different legal concepts. Negligence addresses a failure to exercise reasonable care, resulting in damage or harm, and does not specifically relate to unauthorized property. Liability is a general legal principle relating to responsibility for actions or inactions, not particularly tied to the unauthorized possession of property. Trespass pertains more to entering someone's property without permission. While trespass can touch on issues related to property, it does not specifically address the possession or control of another’s property,