Legal Definitions - invalid

Invalid (in-val-id), adj.

1. Not legally binding, such as an invalid contract.
2. Without basis in fact, such as invalid allegations.

Invalid (in-və-lid), n.

A person who, because of serious illness or other disability, lacks the physical or mental capability of managing his or her day-to-day life.

The word invalid can be used as an adjective or a noun. As an adjective, it means something is not legally binding or without basis in fact. For example, an invalid contract is not legally binding because it does not meet the requirements of the law. Invalid allegations are accusations that are not based on facts or evidence.

As a noun, invalid refers to a person who is unable to manage their day-to-day life due to a serious illness or disability. This could include physical or mental disabilities that prevent them from taking care of themselves.

For example, a person who has suffered a stroke and is unable to move or speak may be considered an invalid because they cannot manage their daily activities without assistance.