The term specificity in this context is related to the field of medicine. It is also known as the true negative rate, and it is a statistical measurement. Specificity measures the amount of negatives to the amount that is correctly identified. In other words, it is the amount of people rightly seen as not having a specific disease or condition.
A negative means the person is healthy, which a positive would mean the person is deceased. Specificity counts how many false negatives are avoided. The opposite of specificity is sensitivity, which is also known as the true positive rate, probability of detection, or recall.