Definition
When used as a legal designation attached to a title, "acting" identifies a person who is temporarily performing the duties of an office without holding — or claiming — that office by lawful appointment. An acting officer is a locum tenens: a placeholder who discharges the functions of the position but derives no permanent title from the role.
The term appears most commonly in two contexts:
1. Acting officer. A person temporarily filling a public or institutional position — Acting Secretary, Acting Commissioner, Acting Director — pending proper appointment of a permanent incumbent. The designation signals that the individual's authority is functional and provisional, not conferred by the ordinary appointment process.
2. Acting executor. A person who assumes the functions of an executor for a decedent's estate without having been legally appointed to that role, whether by will or by court. Distinguished from both a duly appointed executor and an executor de son tort (one who intermeddled without color of authority), an acting executor occupies a practical middle ground — performing the work while lacking formal title.
Common Language
Modern common usage (Wiktionary): present participle and gerund of "act."
Historical common usage (Webster's 1913): "Operating in any way. Doing duty for another; officiating; as, an acting superintendent."
Webster's 1913 sits closer to the legal meaning than most common-language definitions do, capturing the substitutional sense of the word. The legal term is more precise: "acting" in law is not merely doing something, nor is it simply officiating — it specifically marks the absence of a claim to title while exercising the duties of a defined office. The legal significance lies in what the designation withholds, not just what it grants.
Common Confusion
Acting vs. de facto officer. An acting officer typically has some recognized authority or color of appointment — the designation is formal and acknowledged. A de facto officer may hold no formal designation at all, exercising power under a claim or color of title that is later found defective. The two concepts overlap but are not identical: an acting officer may be entirely lawful in their temporary capacity, while de facto status is typically invoked to validate past acts of someone whose title was legally flawed.
Acting executor vs. executor de son tort. An acting executor performs estate functions without legal appointment but without necessarily the wrongful intermeddling that characterizes an executor de son tort. The distinction matters for liability: an executor de son tort may face personal liability for unauthorized acts, while the treatment of an acting executor depends on the circumstances and jurisdiction.
Why It Matters in Research
The term "acting" appears throughout historical administrative, probate, and public law records, and its significance is easy to underread. Researchers should note several traps:
Authority questions. Whether an acting officer's decisions, orders, or signatures carry legal force is a recurring issue in administrative law disputes. Historical records involving an "acting" official may embed questions about whether that officer had authority to bind the government or institution — questions that surface in challenges to contracts, regulations, and appointments.
Probate records. In estate and probate research, "acting executor" is a signal that the decedent's affairs may have been handled by someone without formal appointment. This creates downstream questions about the validity of distributions, conveyances, or account settlements executed by that person.
Shifting usage over time. In modern administrative law, "acting" designates have become governed by statute in the federal context (the Federal Vacancies Reform Act controls who may serve in an acting capacity in executive branch positions). Historical corpus materials predating those statutes treat the term more informally. Do not assume modern statutory constraints apply when reading pre-20th century sources.
Jurisdictional drift in probate. The acting executor concept appears inconsistently across state courts. Some historical decisions treat acting executors with the same scrutiny as executors de son tort; others afford them more latitude. Cross-check with the applicable state's probate statutes and case law rather than generalizing.
Historical Dictionary Support
The historical dictionaries agree on the core meaning with near-identical language: "acting" attached to a title designates a locum tenens who performs the duties of an office without claiming title to it. Black's (both editions), Bouvier's, and Anderson's converge on this definition, with Bouvier's and Anderson's offering the broadest list of examples (acting executor, acting partner, acting commissioner of patents, acting reporter of decisions).
Black's 2nd edition usefully extends the definition into the probate context, treating the acting executor separately as one "who assumes to act as executor for a decedent, not being the executor legally appointed or the executor in fact." This is a meaningful addition that the 1st edition and other dictionaries omit. It signals that by the early 20th century, courts were encountering the concept often enough to warrant its own treatment.
What the historical dictionaries do not address: the constitutional and statutory dimensions of acting appointments in the executive branch, which became contested legal terrain in the 20th and 21st centuries. Researchers using these dictionaries for modern administrative law questions will find them insufficient without supplementation.
Jurisdictional Note
In the federal executive branch, acting officer authority is now regulated by the Federal Vacancies Reform Act of 1998, which restricts who may serve in an acting capacity in Senate-confirmed positions and for how long. State law varies considerably for acting officers in state and local government, and for acting fiduciaries in probate proceedings. Do not import federal statutory rules into state law analysis, or vice versa.