• Webster's Revised Unabridged Dictionary
    • n Urachus (Anat) A cord or band of fibrous tissue extending from the bladder to the umbilicus.
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Century Dictionary and Cyclopedia
    • n urachus In anatomy, a fibrous cord extending from the fundus of the bladder to the umbilicus. It represents in the adult a part of the sac of the allantois and associate allantoic vessels of the fetus, whose cavities have become obliterated. It is that intra-abdominal section of the navel-string which is constituted by so much of the allantoic sac and the hypogastric arteries as becomes impervious, the section remaining pervious being the bladder and superior vesical arteries. It sometimes remains pervious, as a malformation, when a child may urinate by the navel. See also ureter.
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Chambers's Twentieth Century Dictionary
    • n Urachus ū′ra-kus one of the ligaments of the bladder formed by the remaining constricted portion of the allantois of the fœtus.
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Webster's Revised Unabridged Dictionary
NL., fr. Gr. urine + to hold
Chambers's Twentieth Century Dictionary
Gr. ourachosouron, urine.


In literature:

Littre mentions a patent urachus in a boy of eighteen.
"Anomalies and Curiosities of Medicine" by George M. Gould
In very rare cases open urachus may exist without any joint inflammation.
"The Veterinarian" by Chas. J. Korinek
"Special Report on Diseases of the Horse" by United States Department of Agriculture
The cord also contains the urachus (2') which carries urine from the bladder (2) through the cord.
"Special Report on Diseases of Cattle" by U.S. Department of Agriculture
He failed, however, to trace the connexion of the urachus with the bladder.
"Encyclopaedia Britannica, 11th Edition, Volume 13, Slice 1" by Various