Definition
Abbreviation of the Latin *ibidem*, meaning "in the same place." Used in legal writing, scholarly footnotes, and case citations to indicate that a reference is to the same source, volume, page, or passage cited immediately before. Functionally identical to *ibid.* (with period) and interchangeable with *id.* in many citation styles, though conventions vary by context and jurisdiction.
Common Language
Modern common usage (Wiktionary): Alternative form of *ibid.*, meaning "in the same place."
Historical common usage: Not separately entered in Webster's 1913; the term belongs primarily to scholarly and legal Latin abbreviation conventions.
The common and legal meanings are essentially identical here. The only meaningful gap is practical: in everyday academic writing, *ibid.* is the dominant form, while legal writing — particularly in American courts — strongly favors *id.* The choice between forms signals which stylistic tradition a document belongs to.
Common Confusion
IBID vs. ID.: These abbreviations serve the same core function but are not always interchangeable in legal practice. *Id.* (from *idem*, meaning "the same") is the form prescribed by the Bluebook and most American legal citation systems when referring to the immediately preceding authority. *Ibid.* and *ibid* are more common in academic and British legal writing. Researchers encountering older American legal briefs, treatises, or judicial opinions may find *ibid.* or *ibid* used where modern practice would use *id.* The meaning is the same; the form marks the era and tradition.
IBID vs. IDEM: *Ibid.* means the same *place* (same source, same location). *Idem* means the same *person* or *thing*. In classical legal Latin, the distinction mattered; in modern citation shorthand, the line has blurred, and both point practitioners back to the immediately preceding reference.
Why It Matters in Research
Researchers working in the Law Mind corpus will encounter *ibid*, *ibid.*, *ib.*, and *id.* used interchangeably across different periods and traditions. Older English legal treatises and equity reports favor *ibid.*; twentieth-century American legal writing increasingly standardizes on *id.* Understanding this shift prevents misreading a citation chain in historical sources.
When tracing a line of authority through footnotes in older digests, treatises, or appellate briefs, an *ibid* or *ib.* reference points back to the immediately preceding footnote — not necessarily to the same page, and not necessarily to the same volume if the prior note cited a multi-volume work with a specific volume designation. Misidentifying what *ibid.* refers back to is a genuine trap in dense historical footnoting, particularly when an intervening editorial note or compiler's remark breaks the citation chain visually but not logically.
In the Law Mind corpus, *ib.* (the further-abbreviated form noted by Bouvier) appears frequently in nineteenth-century American legal dictionaries and digests. Treat *ib.* and *ibid* as equivalent; both resolve to the prior citation.
Historical Dictionary Support
Both Burrill and Bouvier treat *ibid* minimally, as a pure abbreviation entry pointing to *ibidem*. Bouvier's entry is the more informative of the two, clarifying that *ibidem* covers the same book, place, or subject, and cross-referencing the abbreviations *ib.* and *id.* as related forms. Burrill simply redirects to *ibidem* without elaboration.
Neither source distinguishes *ibid.* from *id.* as a matter of preference or citation convention — a distinction that would become practically significant as American citation systems formalized in the twentieth century. The historical dictionaries reflect an era when abbreviation conventions were fluid and context-dependent rather than governed by a uniform citation manual.
Encyclopedia Cross-Reference
See Law Mind Encyclopedia: Abbreviations in Legal Writing; Citation Forms and Latin Abbreviations.