Definition
A Latin citation signal meaning "below" or "later in this document." When appearing in a legal text, treatise, brief, or judicial opinion, infra directs the reader forward to a passage, section, footnote, or authority that appears later in the same work. It is the functional opposite of supra, which directs the reader backward to something already presented.
In practice, infra functions as a cross-reference tool: "See infra Part III" tells the reader that the relevant discussion, case, or argument has not yet appeared and will be addressed subsequently. It is used both as a standalone signal and as part of a compound reference (e.g., "infra note 47").
Common Language
Modern common usage (Wiktionary): Discussed later.
Historical common usage (Webster's 1913): Below; beneath; under; after — often used as a prefix.
The gap here is minimal but worth noting. In common and prefix usage, infra carries a spatial or structural sense (infrared, infrastructure — meaning beneath or foundational). In legal citation, the spatial metaphor collapses entirely into a temporal or sequential one: infra means not physically below on the page but later in the document's logical order. A reader unfamiliar with legal citation conventions may interpret infra as a general Latin flourish rather than a precise navigational signal.
Common Confusion
Infra is most commonly confused with post, which shares the same directional function — both point the reader forward in a text. Historically, Black's Law Dictionary treated infra and post as near-equivalents for this purpose. The distinction, to the extent one exists in modern usage, is largely stylistic: post is somewhat more common in older English legal writing, while infra is the standard signal in formal American legal citation (particularly under Bluebook convention). Neither term indicates the distance or proximity of the referenced passage.
Infra is also contrasted with supra (above; earlier in this document) and ante (before; in an earlier time or place). Researchers encountering ante in older texts should not assume it functions identically to supra — ante can carry a stronger temporal sense (referring to an earlier point in time or argument) rather than a purely positional one within a document.
Why It Matters in Research
Infra is a navigational term, not a substantive legal concept, but it creates real research friction in several contexts.
In historical legal texts and treatises, infra cross-references assume a fixed document structure that may not survive digitization, reprinting, or abridgment. A nineteenth-century treatise using "infra, p. 412" may reference a page that has shifted in a modern reprint, been omitted in an abridged edition, or landed in a different volume entirely. Researchers using Law Mind's historical corpus should treat infra references as clues requiring independent verification rather than reliable navigation.
In judicial opinions, infra signals that a court is previewing a point it will elaborate later — useful for understanding the structure of an argument but not a substitute for reading the referenced passage in full. Infra references in opinions are not always indexed or hyperlinked in older digitized collections.
The infra/supra pair creates a specific trap in case law research: when opinions are excerpted in reporters or secondary sources, cross-references using infra or supra may become meaningless or misleading because the surrounding text has been removed. A passage flagged as "see infra" in a full opinion may have no corresponding target in an edited version.
Finally, in the Law Mind corpus, infra will appear with high frequency in treatises, digests, and annotated codes — almost always as a citation signal rather than as a substantive term. Search results for "infra" without context filtering will return enormous volumes of navigational noise. Researchers targeting substantive content should filter accordingly.
Historical Dictionary Support
Black's Law Dictionary (both the first and second editions) and Burrill's Law Dictionary agree precisely on the core meaning: infra means "below; underneath; within," functioning within a text as a forward reference equivalent to post, and standing as the opposite of both ante and supra. This is the clearest point of consensus across the historical shelf.
Burrill adds the most texture, supplying the Latin grammatical context — infra as the correlative of supra in degree-of-relationship tables (pater/mater above, filius/filia below) — which illuminates how deeply spatial the term's root meaning is, even as legal citation repurposes it sequentially. Burrill's entry also transitions into a discussion of criminal informations, reflecting how historical dictionaries sometimes used infra entries as launch points for related substantive terms, which can mislead a researcher scanning quickly.
The Rapalje & Lawrence and Anderson's entries in the source material do not supply usable definitions for infra as a citation signal — their text appears to reflect cross-reference artifacts or adjacent entries rather than substantive treatment of the term. Researchers relying on those sources for this term will find no additional analytical value beyond what Black's and Burrill provide.
Encyclopedia Cross-Reference
See Law Mind Encyclopedia: Citation Signals and Cross-Reference Conventions; Latin Terms in Legal Writing.