In biology, any of a group of cyclic,
unsaturated alcohols (lipids without fatty
acid components), which, like sterols, have a
complex molecular structure consisting of
four carbon rings. Steroids include the sex
hormones, such as testosterone, the
corticosteroid hormones produced by the
adrenal gland, bile acids, and cholesterol.
The term is commonly used to refer to
anabolic steroid.