1.  syndrome(n = noun.cognition) - a complex of concurrent things; "every word has a syndrome of meanings"
is a kind of complex, composite

2.  syndrome(n = noun.state) - a pattern of symptoms indicative of some disease;
is a kind of symptom
is a part of disease
has particulars: autism, add, adhd, attention deficit disorder, attention deficit hyperactivity disorder, hyperkinetic syndrome, mbd, minimal brain damage, minimal brain dysfunction, horner's syndrome, cervical disc syndrome, cervical root syndrome, chinese restaurant syndrome, conn's syndrome, fas, fetal alcohol syndrome, gulf war syndrome, persian gulf illness, klinefelter's syndrome, klinefelter syndrome, xxy-syndrome, malabsorption syndrome, munchausen's syndrome, munchausen syndrome, nephrosis, nephrotic syndrome, noonan's syndrome, phantom limb syndrome, pms, premenstrual syndrome, radiation, radiation sickness, radiation syndrome, ramsay hunt syndrome, reiter's disease, reiter's syndrome, ekbom syndrome, restless legs, restless legs syndrome, reye's syndrome, scalenus syndrome, apyretic tetanus, intermittent cramp, intermittent tetanus, tetanilla, tetany, thoracic outlet syndrome, tietze's syndrome, gilles de la tourette syndrome, tourette's syndrome, fallot's syndrome, fallot's tetralogy, tetralogy of fallot, toxic shock, toxic shock syndrome, tss, waterhouse-friderichsen syndrome, williams syndrome, zollinger-ellison syndrome

1.  Concurrence. Glanvill. [1913 Webster]

2.  A group of symptoms occurring together that are characteristic and indicative of some underlying cause, such as a disease. [1913 Webster]

3.  generally, a pattern of characteristics or behaviors occurring together, that are sufficiently common and distinctive to indicate that they are due to a known cause. [PJC]

syndrome, n.
1 a group of concurrent symptoms of a disease.
2 a characteristic combination of opinions, emotions, behaviour, etc.

Derivative:
syndromic adj.

Etymology:
mod.L f. Gk sundrome (as SYN-, drome f. dramein to run)

acquired immune deficiency syndrome, acute organic brain syndrome, adams-stokes syndrome, addison's syndrome, adult respiratory distress syndrome, banti's syndrome, binge-eating syndrome, binge-purge syndrome, binge-vomit syndrome, carpal tunnel syndrome, cervical disc syndrome, cervical root syndrome, chinese restaurant syndrome, conn's syndrome, cushing's syndrome, down syndrome, down's syndrome, eaton-lambert syndrome, ekbom syndrome, fallot's syndrome, fetal alcohol syndrome, gilles de la tourette syndrome, guillain-barre syndrome, gulf war syndrome, horner's syndrome, hurler's syndrome, hyperkinetic syndrome, irritable bowel syndrome, kallman's syndrome, klinefelter syndrome, klinefelter's syndrome, korsakoff's syndrome, korsakov's syndrome, lambert-eaton syndrome, malabsorption syndrome, marfan's syndrome, mucocutaneous lymph node syndrome, munchausen syndrome, munchausen's syndrome, myasthenic syndrome, nephrotic syndrome, noonan's syndrome, organic brain syndrome, parkinson's syndrome, phantom limb syndrome, premenstrual syndrome, radiation syndrome, ramsay hunt syndrome, reiter's syndrome, respiratory distress syndrome, respiratory distress syndrome of the newborn, restless legs syndrome, reye's syndrome, scalenus syndrome, severe acute respiratory syndrome, stokes-adams syndrome, sudden infant death syndrome, thoracic outlet syndrome, tietze's syndrome, tourette's syndrome, toxic shock syndrome, turner's syndrome, waterhouse-friderichsen syndrome, williams syndrome, zollinger-ellison syndrome