Before we discuss, what do accessory symptom of disease mean, let's discuss what does “accessory” word mean? Accessory word is used in relation to many things, whether it is home, machine or individual himself or herself. Accessories are provided separately with them. They does not make the whole home, machine or individual but they are purchased separately and used conjointly with them; Same applies to accessory symptoms of disease, they occur conjointly in relation to disease. Image Source - https://de.m.wikipedia.org/wiki/Datei:Snake_bite_symptoms.png