The Collaborative International Dictionary of English v.0.48:

Hydrophobia \Hy`dro*pho"bi*a\, n. [L., fr. Gr. ?; "y`dwr water +
   ? fear: cf. F. hydrophobie.] (Med.)
   (a) An abnormal dread of water, said to be a symptom of
       canine madness; hence:
   (b) A viral disease trransmitted by a bite from, or
       inoculation with the saliva of, a rabid creature, of
       which the chief symptoms are, a sense of dryness and
       constriction in the throat, causing difficulty in
       deglutition, and a marked heightening of reflex
       excitability, producing convulsions whenever the patient
       attempts to swallow, or is disturbed in any way, as by
       the sight or sound of water; rabies; canine madness.
       [Written also hydrophoby.]
       [1913 Webster]

WordNet (r) 3.0 (2006):

hydrophobia
    n 1: a symptom of rabies in humans consisting of an aversion to
         swallowing liquids
    2: a morbid fear of water
    3: an acute viral disease of the nervous system of warm-blooded
       animals (usually transmitted by the bite of a rabid animal);
       rabies is fatal if the virus reaches the brain [syn:
       rabies, hydrophobia, lyssa, madness]

Moby Thesaurus II by Grady Ward, 1.0:

179 Moby Thesaurus words for "hydrophobia":
   African lethargy, Asiatic cholera, Chagres fever, German measles,
   Haverhill fever, Texas fever, acute articular rheumatism, ague,
   alkali disease, amathophobia, amebiasis, amebic dysentery, anthrax,
   aphthous fever, bacillary dysentery, bastard measles, bighead,
   black death, black fever, black quarter, blackleg, blackwater,
   blackwater fever, blennophobia, blind staggers, bloody flux,
   breakbone fever, broken wind, brucellosis, bubonic plague,
   cachectic fever, canine madness, cattle plague,
   cerebral rheumatism, chaetophobia, charbon, chicken pox, cholera,
   cowpox, dandy fever, deer fly fever, dengue, dengue fever,
   diphtheria, distemper, dumdum fever, dysentery, elephantiasis,
   encephalitis lethargica, enteric fever, erysipelas, famine fever,
   five-day fever, flu, foot-and-mouth disease, frambesia,
   furious rabies, gapes, glanders, glandular fever, grippe,
   hansenosis, heaves, hemaphobia, hematophobia, hepatitis, herpes,
   herpes simplex, herpes zoster, histoplasmosis, hog cholera,
   hoof-and-mouth disease, hookworm, infantile paralysis,
   infectious mononucleosis, inflammatory rheumatism, influenza,
   jail fever, jungle rot, kala azar, kissing disease, koniophobia,
   lepra, leprosy, leptospirosis, liver rot, loa loa, loaiasis,
   lockjaw, loco, loco disease, locoism, mad staggers, madness,
   malaria, malarial fever, malignant catarrh,
   malignant catarrhal fever, malignant pustule, mange, marsh fever,
   measles, megrims, meningitis, milzbrand, monophobia, mumps,
   ornithosis, osteomyelitis, panphobia, paratuberculosis,
   paratyphoid fever, parotitis, parrot fever, pertussis, pip,
   pneumonia, polio, poliomyelitis, polyarthritis rheumatism, ponos,
   pseudotuberculosis, psittacosis, quarter evil, rabbit fever,
   rabies, rat-bite fever, relapsing fever, rheumatic fever,
   rickettsialpox, rinderpest, ringworm, rot, rubella, rubeola,
   scabies, scarlatina, scarlet fever, schistosomiasis,
   septic sore throat, sheep rot, shingles, sleeping sickness,
   sleepy sickness, smallpox, snail fever, splenic fever,
   spotted fever, staggers, strep throat, stringhalt, sullen rabies,
   swamp fever, swine dysentery, tetanus, thrush, tinea, toxiphobia,
   toxophobia, trench fever, trench mouth, tuberculosis, tularemia,
   typhoid, typhoid fever, typhus, typhus fever, undulant fever,
   vaccinia, varicella, variola, venereal disease, viral dysentery,
   whooping cough, yaws, yellow fever, yellow jack, zona, zoster