Definition
A historical legal term with two related applications, both rooted in the concept of playing both sides simultaneously.
1. An attorney who secretly took fees or payment from both parties to a dispute — serving opposing clients at the same time while ostensibly representing only one.
2. A juror who accepted money from both sides of a case, effectively selling a verdict to whichever party paid more, or corrupting the jury process by taking bribes from multiple parties.
Both usages were treated as serious professional and ethical violations. The term is largely archaic in modern legal writing but appears with some regularity in historical legal texts and early common law commentary.
Common Language
Modern common usage (Wiktionary): Ambidextrous.
Historical common usage (Webster's 1913): "Using both hands with equal ease."
The legal term exploits the common meaning as a metaphor: just as an ambidextrous person is equally capable with either hand, the ambidexter lawyer or juror was equally willing to work for either side — simultaneously and corruptly. The common meaning is neutral or even complimentary; the legal meaning was entirely pejorative, denoting fraud and betrayal of duty.
Common Confusion
Ambidexter should not be confused with mere dual representation or conflicts of interest in their modern sense. Contemporary conflicts doctrine governs attorneys who represent adverse parties, but it operates through disclosure, consent, and withdrawal rules — not the criminal or quasi-criminal framing that surrounded ambidexter conduct historically. The ambidexter was not a lawyer who disclosed a conflict; he was one who concealed double-dealing for personal gain. Researchers working across historical and modern sources should be careful not to import the modern conflicts-of-interest framework backward onto ambidexter references, or vice versa.
Why It Matters in Research
Ambidexter is an essentially dead term in modern practice but surfaces repeatedly in early English and American legal sources. Researchers consulting Cowell's Interpreter, early editions of Black's, or colonial-era legal commentary will encounter it without explanation. Understanding that the term always carries a double meaning — the attorney variant and the juror variant — is essential to reading those passages correctly.
The juror application is particularly significant for researchers examining the history of jury corruption, jury tampering, and the development of contempt powers. Early common law treated jury bribery as a distinct and serious offense, and ambidexter was the standard term of art for the corrupt juror in that framework.
For legal history researchers, the attorney variant connects to the long development of professional responsibility, fiduciary duty, and the prohibition on representing adverse interests. The modern duty of loyalty has direct historical roots in the prohibition on ambidexter conduct, though the language has entirely changed.
Researchers should note that Black's first and second editions carry nearly identical entries, both citing Cowell. Rapalje & Lawrence tracks the same definition without significant deviation. There is no meaningful divergence across these shelf sources, which suggests the term had a stable and settled meaning by the time these dictionaries were compiled — and that its use was already becoming historical rather than current even then.
Historical Dictionary Support
All three source dictionaries are in substantial agreement. Black's (both editions) and Rapalje & Lawrence define the term consistently: a person who plays both sides, applied first to attorneys taking double fees and subsequently to jurors guilty of the same conduct. All three cite or implicitly rely on Cowell's Interpreter as the authoritative historical source.
None of the dictionaries provide a modern application or suggest the term remained in active use at the time of their publication. The framing in all three is antiquarian — "anciently" and "subsequently" signal that even nineteenth-century lexicographers were describing a historical concept rather than current practice.
What the historical dictionaries miss: none of them explore the relationship between ambidexter conduct and the formal development of conflicts-of-interest doctrine, nor do they connect the juror variant to the broader history of attaint — the ancient remedy for corrupt verdicts. Researchers interested in those connections will need to go beyond the dictionary sources.
Encyclopedia Cross-Reference
See Law Mind Encyclopedia: Conflicts of Interest (Attorney); Jury Corruption and Tampering; History of Professional Responsibility.