A more thorough explanation:

In legal interpretation, the term-of-art canon is a principle that states that if a word or phrase has a specialized or technical meaning in a particular field or context, it should be assumed to have that meaning when used in that context.

For example, the term "battery" has a specific legal meaning in the context of criminal law, referring to the intentional and unlawful touching of another person in a harmful or offensive manner. If the term "battery" appears in a statute related to criminal law, it should be assumed to have this specialized meaning rather than its more general meaning of an electrical power source.

Another example is the term "fiduciary," which has a specific meaning in the context of trust and estate law, referring to a person who has a legal duty to act in the best interests of another person or entity. If the term "fiduciary" appears in a statute related to trust and estate law, it should be assumed to have this specialized meaning rather than its more general meaning of someone who is trustworthy.

The term-of-art canon helps to ensure that legal language is interpreted consistently and accurately, taking into account the specialized meanings of words and phrases in different fields of law.