Definition
An obsolete unit of English currency valued at two pence (2d.). Sicius appears in historical English legal records as a denomination of money and was used primarily in medieval and early modern legal instruments, accounting records, and pleadings where precise monetary denominations were required.
Why It Matters in Research
Sicius is a term researchers are likely to encounter only in pre-modern English legal documents — writs, contracts, fines, and court records from the medieval and early modern periods. Its significance in the Law Mind corpus is almost entirely antiquarian: the term does not carry forward into modern practice and carries no jurisdictional variation in contemporary law.
The primary research trap is misreading the denomination. Two pence (2d.) in historical English currency operates within the pre-decimal system of pounds, shillings, and pence (£/s/d), and researchers working with older instruments must resist converting historical monetary values into modern equivalents without accounting for the enormous purchasing-power difference. A sum denominated in sicius in a medieval record is not trivially small in its original economic context, even though two pence sounds negligible today.
Researchers consulting Rapalje & Lawrence should note that the entry for sicius appears to have suffered a typographical or editorial error in surviving copies: the definition bleeds into a separate entry for "SICKNESS" mid-sentence, likely a printing artifact. This has no substantive effect on the sicius definition itself, which all three source dictionaries state consistently, but it is worth flagging so researchers do not treat the Rapalje & Lawrence entry as authoritative on the sickness cases cited immediately after the corruption.
No known American legal authority has occasion to apply or interpret sicius, and it does not appear in modern statutory or common law. Its value lies entirely in decoding historical documents.
Historical Dictionary Support
All three source dictionaries — Black's Law Dictionary, Black's Law Dictionary (2nd Ed.) Supplemental, and Rapalje & Lawrence — agree exactly: sicius denotes a form of money current among the ancient English, valued at 2d. There is no divergence on substance. The uniformity suggests the later editions drew directly from the first without independent research, which is typical for rare archaic monetary terms that had no living legal application by the time these dictionaries were compiled.
None of the historical dictionaries provide additional context about the period of use, the instruments in which sicius appeared, or how the denomination related to the broader pre-decimal English monetary system. Researchers needing that context must consult numismatic and economic history sources outside the legal dictionary tradition. The historical legal dictionaries treat sicius as a curiosity — worth defining for completeness, but not a term around which doctrine developed.