The Collaborative International Dictionary of English v.0.48:

Dyspepsia \Dys*pep"si*a\, Dyspepsy \Dys*pep"sy\ (?; 277), [L.
   dyspepsia, Gr. ?, fr. ? hard to digest; dys- ill, hard + ? to
   cook, digest; akin to E. cook: cf. F. dyspepsie. See Dys-,
   and 3d Cook.] (Med.)
   A kind of indigestion; a state of the stomach in which its
   functions are disturbed, without the presence of other
   diseases, or, if others are present, they are of minor
   importance. Its symptoms are loss of appetite, nausea,
   heartburn, acrid or fetid eructations, a sense of weight or
   fullness in the stomach, etc. --Dunglison. Dyspeptic

WordNet (r) 3.0 (2006):

dyspepsia
    n 1: a disorder of digestive function characterized by
         discomfort or heartburn or nausea [syn: indigestion,
         dyspepsia, stomach upset, upset stomach]

Moby Thesaurus II by Grady Ward, 1.0:

83 Moby Thesaurus words for "dyspepsia":
   abscess, ague, anemia, ankylosis, anoxia, apnea, asphyxiation,
   asthma, ataxia, atrophy, backache, bleeding, blennorhea, cachexia,
   cachexy, cardialgia, chill, chills, cholera morbus, colic,
   constipation, convulsion, costiveness, coughing, cyanosis,
   diarrhea, dizziness, dropsy, dysentery, dyspnea, edema, emaciation,
   fainting, fatigue, fever, fibrillation, flux, gripe, gripes,
   growth, heartburn, hemorrhage, high blood pressure, hydrops,
   hypertension, hypotension, icterus, indigestion, inflammation,
   insomnia, irregularity, itching, jaundice, labored breathing,
   lientery, low blood pressure, lumbago, marasmus, nasal discharge,
   nausea, necrosis, obstipation, pain, paralysis, pruritus, pyrosis,
   rash, rheum, sclerosis, seizure, shock, skin eruption, sneezing,
   sore, spasm, tabes, tachycardia, trots, tumor, upset stomach,
   vertigo, vomiting, wasting



Bouvier's Law Dictionary, Revised 6th Ed (1856):

DYSPEPSIA, med. jur., contracts. A state of the stomach in which its
functions are disturbed, without the presence of other diseases; or when, if
other diseases are present, they are of minor importance. Dunglison's Med.
Dict. h.t.
     2. Dyspepsia is not, in general, considered as a disease which tends to
shorten life, so as to make a life uninsurable; unless the complaint has
become organic dyspepsia, or was of such a degree at the time of the
insurance, as, by its excess, to tend to shorten life. 4 Taunt. 763.