Definitions of tangent

a
straight
line
or
plane
that
touches
a
curve
or
curved
surface
at
a
point
but
does
not
intersect
it
at
that
point

A
tangent
line
curve,
or
surface;
specifically,
that
portion
of
the
straight
line
tangent
to
a
curve
that
is
between
the
point
of
tangency
and
a
given
line,
the
given
line
being,
for
example,
the
axis
of
abscissas,
or
a
radius
of
a
circle
produced.
See
Trigonometrical
function,
under
Function.

A
straight
line
that
meets
or
touches
a
circle
or
curve,
but
does
not
cut
it;
any
line
or
course
leading
abruptly
away
from
the
usual
course.

A
right
line
which
merely
touches
a
curve.

A
straight
line
tangent
to
a
curve.

A
right
line
which
touches
a
curve,
but
which,
when
produced,
does
not
cut
it.
Tangent
of
an
arc,
a
right
line
drawn
touching
one
extremity
of
the
arc,
and
limited
by
a
secant
or
line
drawn
through
the
centre
and
the
other
extremity.

In
trig.
and
geom.,
a
straight
line
which
touches
a
circle
or
curve,
but
though
produced,
does
not
cut
it.

Touching;
touching
at
a
single
point

meeting
a
curve
or
surface
at
a
point
and
having
at
that
point
the
same
direction
as
the
curve
or
surface; 
said
of
a
straight
line,
curve,
or
surface;
as,
a
line
tangent
to
a
curve;
a
curve
tangent
to
a
surface;
tangent
surfaces.

Touching;
in
geometry,
meeting
a
curve
only
at
one
point,
but
not
cutting
it.

Geom.
Touching
a
line
or
a
surface
at
one
point
only.

Touching.
X