Real Dictionary

hypothalamus
The hypothalamus is a part of the brain that links the nervous system to the glands in the body that produce hormones. It is involved in controlling emotions, hunger, thirst, and sleep.

hypothalamus in American English
the part of the diencephalon in the brain that forms the floor of the third ventricle and regulates many basic body functions, as temperature
noun: a region of the brain, between the thalamus and the midbrain, that functions as the main control center for the autonomic nervous system by regulating sleep cycles, body temperature, appetite, etc., and that acts as an endocrine gland by producing hormone

hypothalamus in British English
noun: a neural control centre at the base of the brain, concerned with hunger, thirst, satiety, and other autonomic functions