Noun
A
natural
estrogenic
hormone
that
is
a
phenolic
alcohol
5-triene-3
,
17-diol
()
secreted
chiefly
by
the
ovaries
of
all
vertebrates
,
that
is
a
major
and
the
most
potent
of
the
naturally
occurring
estrogens
;
the
semisynthetic
esterified
compound
is
used
medicinally
to
treat
estrogen deficiency
and
breast cancer
.