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.
1 Swollen neck lymph nodes and Thyroid problems and Swelling symptoms (5 causes). 2  Swollen neck lymph nodes and Thyroid problems and Swollen glands (5 causes). 3  Swollen neck lymph nodes and Thyroid problems and Swollen lymph nodes (5 causes).4  Swollen neck lymph nodes and Thyroid problems and Thyroid symptoms (5 causes).wollen neck lymph nodes: 1  212 causes: Swollen neck lymph nodes. 2  Introduction: Swollen neck lymph nodes. 3  Swollen neck lymph nodes: Add a 3rd symptom. 4  Swollen neck lymph nodes: Remove a symptom.