I believe they mean that the random variables have a common support. For example, if X ~ Unif[0,2] and Y ~ Unif[1,3], then their respective PDF's overlap in the interval [1,2], meaning the only interval where both X and Y can have common values is [1,2]. To illustrate, below is a representation of the supports of X and Y, below which is a representation of the real line.
1 Thyroid cancer is a malignant tumor of the thyroid gland. 2  Symptoms of thyroid cancer include swelling in the neck (goiter), neck pain, hoarseness, swallowing and breathing problem, swollen lymph gland in the neck.
Many people with Hashimotoâs disease have no symptoms at first. As the disease slowly progresses, the thyroid usually enlarges and may cause the front of the neck to look swollen. The enlarged thyroid, called a goiter, may create a feeling of fullness in the throat, though it is usually not painful.