A tangent line.
A tangent line touches a curve or the circumference of a circle at just one point.
A straight line that intersects a circle or curve at two points, but which has both end points outside the circle or curve is called a secant. A straight line that links two points on a circle or curve is called a chord. A straight line which touches a circle or curve at one point is called a tangent. A straight line that cuts a circle or curve at one point is a straight line.* For moving diagrams see Related links below this box.
A curve.
The set of points on a straight curve that extends to infinity in both directions is a line. A ray is the set of points that lie on a straight curve that is terminated at a point, and continues to infinity. It is also called a half-line. If the set is terminated at a point at both ends, then it is a line segment.
A circle doesn't have line segments. It is a curve, not made up of straight lines.A circle doesn't have line segments. It is a curve, not made up of straight lines.A circle doesn't have line segments. It is a curve, not made up of straight lines.A circle doesn't have line segments. It is a curve, not made up of straight lines.
It is a tangent line
A tangent line touches a curve or the circumference of a circle at just one point.
A tangent, but it (a) has nothing to do with croosing (whatever that may mean); and (b) while it does not cross the curve in the neighbourhood of the point of contact - there is no restriction on it crossing the curve at a distance.
Tangent
In geometry a straight line that touches a curve is called a tangent.
It is a straight line that touches the curve such that the line is perpendicular to the radius of the curve at the point of contact.
tangent
A tangent at that point where a straight line just touches a curve and a secant line when the straight line bisects the curve.
A tangent
A tangent. And it does not need to be a circle - it can be any curve.
A straight line that intersects a circle or curve at two points, but which has both end points outside the circle or curve is called a secant. A straight line that links two points on a circle or curve is called a chord. A straight line which touches a circle or curve at one point is called a tangent. A straight line that cuts a circle or curve at one point is a straight line.* For moving diagrams see Related links below this box.
The answer depends on the context. In the context of a curve, a tangent is a straight line that touches the line without intersecting it. The antonym does not have a specific name because it could be a straight line that does not meet the curve at all, or it could be one that crosses the curve. Note that even a tangent can cross the curve at some other [distant] point(s).