Definition
A member of a senate — a legislative body, typically the upper chamber of a bicameral legislature. In American law, the term refers to an elected member of the United States Senate or of a state senate. At the federal level, senators are constitutionally prescribed as two per state, serving six-year terms, and are chosen by popular vote since ratification of the Seventeenth Amendment (1913). State senators serve under terms and qualifications set by individual state constitutions.
The term carries additional historical meanings in legal sources:
1. Roman law: A member of the senatus, the governing council of Rome. Roman law dictionaries treat this as the primary definition, which explains the Latin maxim appearing in historical legal sources.
2. Saxon law: An alderman — a usage found in Burrill and Rapalje & Lawrence that has no modern American legal counterpart.
3. Old English law: A member of the king's council, or king's councillor. This usage is preserved in the maxim Senatores sunt partes corporis regis ("Senators/councillors are part of the body of the king"), cited in Staunford and Coke's Institutes.
Common Language
Modern common usage (Wiktionary): The title for someone who is elected to be a senator.
Historical common usage (Webster's 1913): A member of a senate; also used in the older sense of a member of the king's council, a king's councillor.
The gap between common and legal usage is primarily historical, not conceptual. The common reader understands a senator as an elected legislative official. Historical legal sources, however, use the term across three distinct systems — Roman, Saxon, and English — where it variously described appointed council members, not elected legislators. Researchers reading old English law sources must not assume an elective or legislative function when the word senator appears.
Why It Matters in Research
The principal research trap is anachronism. A researcher encountering senator in a medieval English law source is not reading about an elected legislator — the term there signals membership in an advisory royal council, carrying the constitutional implication expressed in the Latin maxim: such councillors were considered incorporated into the body of the king, with the legal consequences that implied for privilege, authority, and liability.
The Seventeenth Amendment is a significant corpus marker for federal-level sources. Before 1913, U.S. senators were elected by state legislatures, not by popular vote. Legal materials discussing the qualifications, selection, or removal of senators dated prior to that amendment require attention to this structural difference. The constitutional framework governing senators — qualifications, immunity under the Speech or Debate Clause, expulsion, and resignation — is a distinct research cluster separate from the bare definitional question of who a senator is.
State senate research requires jurisdiction-specific attention. Term lengths, qualifications, district apportionment rules, and recall mechanisms vary significantly and are governed by state constitutional provisions rather than federal law.
The Saxon usage (senator as alderman) appears only in Burrill and Rapalje & Lawrence among the shelf sources. Researchers in early English legal history following a citation trail that leads to this sense will not find it in Black's, which omits the Saxon layer.
Historical Dictionary Support
The four shelf sources agree on the Roman law core and the old English law meaning, but with instructive differences in emphasis and completeness.
Black's (both editions) presents the American law sense first — practically oriented — before moving to Roman and English law contexts. Rapalje & Lawrence is notable for explicitly connecting the Roman senatus usage to American law, treating the line of descent as direct and unbroken. Burrill is the most historically complete: it includes the Saxon alderman usage, provides the Digest citation (Dig. 1.9) for the Roman sense, and quotes the Latin maxim with the additional explanatory phrase "they are incorporated to the king" — language that the other sources truncate or omit. That phrase has substantive legal significance, as it grounded certain privileges and immunities of the royal council in the fiction of corporate unity with the crown.
The Latin maxim Senatores sunt partes corporis regis appears in all four sources, attributed consistently to Staunford's Pleas of the Crown and Coke's Institutes (4 Inst. 53). This cross-citation is reliable.
What the historical dictionaries collectively miss: they offer no treatment of the constitutional structure governing modern American senators — the Qualifications Clause, the Speech or Debate Clause, Senate rules on expulsion, or the Seventeenth Amendment. For those questions, the dictionaries are staging points only.
Encyclopedia Cross-Reference
See Law Mind Encyclopedia: Congress (Legislative Branch); Roman Law Institutions; Saxon and Early English Law Councils.