The Collaborative International Dictionary of English v.0.48:

Urine \U"rine\, v. i.
   To urinate. [Obs.] --Bacon.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Urine \U"rine\, n. [F. urine, L. urina; akin to urinari to
   plunge under water, to dive, Gr. ? urine; cf. Skr. v[=a]r
   water, Icel. ?r drizzling rain, AS. w[ae]r the sea.]
   (Physiol.)
   In mammals, a fluid excretion from the kidneys; in birds and
   reptiles, a solid or semisolid excretion.
   [1913 Webster]

   Note: In man, the urine is a clear, transparent fluid of an
         amber color and peculiar odor, with an average density
         of 1.02. The average amount excreted in 24 hours is
         from 40 to 60 ounces (about 1,200 cubic centimeters).
         Chemically, the urine is mainly an aqueous solution of
         urea, salt (sodium chloride), and uric acid, together
         with some hippuric acid and peculiar pigments. It
         usually has an acid reaction, owing to the presence of
         acid phosphates of soda or free uric acid. Normally, it
         contains about 960 parts of water to 40 parts of solid
         matter, and the daily average excretion is 35 grams
         (540 grains) of urea, 0.75 gram (11 grains) of uric
         acid, and 16.5 grams (260 grains) of salt. Abnormally,
         it may contain sugar as in diabetes, protein as in
         Bright's disease, bile pigments as in jaundice, or
         abnormal quantities of some one or more of the normal
         constituents.
         [1913 Webster]

WordNet (r) 3.0 (2006):

urine
    n 1: liquid excretory product; "there was blood in his urine";
         "the child had to make water" [syn: urine, piss, pee,
         piddle, weewee, water]

Moby Thesaurus II by Grady Ward, 1.0:

40 Moby Thesaurus words for "urine":
   chyle, colostrum, discharge, gleet, humor, ichor, lachryma,
   lactation, leukorrhea, lymph, matter, micturition, milk, mucor,
   mucus, peccant humor, pee, pee-pee, phlegm, piddle, pish, piss,
   purulence, pus, rheum, saliva, sanies, serous fluid, serum, snot,
   stale, suppuration, sweat, tear, teardrop, the whites, urea,
   urination, water, wee-wee