The Collaborative International Dictionary of English v.0.48:

atherosclerosis \ath`er*o*scle*ro"sis\
   ([a^]th`[~e]r*[-o]*skl[-e]*r[=o]"s[i^]s), n. [Gr. ? + -logy.]
   (Med.)
   a form of arteriosclerosis characterized by irregular fatty
   deposits on the inner surface of large and medium-sized
   arteries; the deposits are associated with fibrosis and
   calcification of the inner layer of the arteries. Similar
   conditions may be found in swine and fowl. The deposits may
   become large enough to impede the blood circulation and in
   some cases may restrict the blood supply to the heart.
   --Stedman
   [PJC]

WordNet (r) 3.0 (2006):

atherosclerosis
    n 1: a stage of arteriosclerosis involving fatty deposits
         (atheromas) inside the arterial walls, thus narrowing the
         arteries [syn: atherosclerosis, coronary artery
         disease]

Moby Thesaurus II by Grady Ward, 1.0:

96 Moby Thesaurus words for "atherosclerosis":
   angina, angina pectoris, aortic insufficiency, aortic stenosis,
   apoplectic stroke, apoplexy, arrhythmia, arteriosclerosis,
   atrial fibrillation, auricular fibrillation, beriberi heart,
   calcification, callusing, cardiac arrest, cardiac insufficiency,
   cardiac shock, cardiac stenosis, cardiac thrombosis, carditis,
   case hardening, concretion, congenital heart disease,
   cor biloculare, cor juvenum, cor triatriatum, cornification,
   coronary, coronary insufficiency, coronary thrombosis,
   crystallization, diastolic hypertension, encased heart,
   endocarditis, extrasystole, fatty heart, fibroid heart, firming,
   flask-shaped heart, fossilization, frosted heart, granulation,
   hairy heart, hardening, heart attack, heart block, heart condition,
   heart disease, heart failure, high blood pressure, hornification,
   hypertension, hypertensive heart disease, induration,
   ischemic heart disease, lapidification, lithification,
   mitral insufficiency, mitral stenosis, myocardial infarction,
   myocardial insufficiency, myocarditis, myovascular insufficiency,
   ossification, ox heart, palpitation, paralytic stroke,
   paroxysmal tachycardia, pericarditis, petrifaction, petrification,
   pile, premature beat, pseudoaortic insufficiency,
   pulmonary insufficiency, pulmonary stenosis,
   rheumatic heart disease, round heart, sclerosis, setting,
   solidification, steeling, stiffening, stony heart, stroke,
   tachycardia, tempering, thrombosis, toughening,
   tricuspid insufficiency, tricuspid stenosis, turtle heart,
   varicose veins, varix, ventricular fibrillation, vitrifaction,
   vitrification