A more thorough explanation:

Term: Mental Competency
Definition: Mental competency refers to a person's ability to make informed decisions and understand the consequences of their actions. It is the ability to understand and participate in legal proceedings, such as signing a contract or making a will. Mental competency is often evaluated by medical professionals and legal authorities to determine if a person is capable of making decisions for themselves.
Example: An elderly person with dementia may not have the mental competency to make decisions about their medical care or finances. In this case, a legal guardian may be appointed to make decisions on their behalf.
Explanation: The example illustrates how mental competency is important in making decisions that affect a person's life. In this case, the elderly person's dementia affects their ability to make decisions, so someone else is appointed to make decisions for them. This is done to protect the person's best interests and ensure that their decisions are made in a competent manner.