元となった辞書の項目
sidereal year
noun
The
orbital
period
of
the
Earth;
a
measure
of
the
time
it
takes
for
the
Sun
to
return
to
the
same
position
with
respect
to
the
stars
of
the
celestial
sphere.
A
sidereal
year
is
about
20.4
minutes
longer
than
the
tropical
year
(which
is
what
is
kept
stable
by
the
Gregorian
calendar)
due
to
precession
of
the
equinoxes.
意味（1）
The
orbital
period
of
the
Earth;
a
measure
of
the
time
it
takes
for
the
Sun
to
return
to
the
same
position
with
respect
to
the
stars
of
the
celestial
sphere.
A
sidereal
year
is
about
20.4
minutes
longer
than
the
tropical
year
(which
is
what
is
kept
stable
by
the
Gregorian
calendar)
due
to
precession
of
the
equinoxes.
