subarachnoid space: a space in the meninges beneath the arachnoid membrane and above the pia mater that contains the cerebrospinal fluid
space: an empty area (usually bounded in some way between things)
hypogonadism: incompetence of the gonads (especially in the male with low testosterone); results in deficient development of secondary sex characteristics and (in prepubertal males) a body with long legs and a short trunk