A steroid hormone.
[A blend of steroid with ketone.]
Such compounds are steroids that are also ketones, containing a carboxyl group (==C==O). Examples include the naturally occurring sex hormones progesterone (Latin pro plus the first part of gestation), testosterone (Latin testis, a witness (to fertility)), and androsterone (Greek anēr, andr-, man). Other examples are aldosterone (English aldehyde), a corticosteroid hormone which stimulates absorption of sodium by the kidneys and so regulates water and salt balance, and corticosterone, a hormone secreted by the adrenal cortex.