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.
Problems with the thyroid include overactive thyroid, or hyperthyroidism, and underactive thyroid or hypothyroidism. The thyroid gland in the neck makes hormones to help regulate the body's metabolism and a person's growth.An overactive thyroid can make a person feel nervousness or anxious, be hyperactive and experience unexpected weight loss.he thyroid gland in the neck makes hormones to help regulate the body's metabolism and a person's growth. An overactive thyroid can make a person feel nervousness or anxious, be hyperactive and experience unexpected weight loss.