The term you are describing is a line.
A line
A straight line with no endpoints is a geometric concept that extends infinitely in both directions. It is often represented in mathematics by a line symbol, denoted by two points on the line or with a single letter. Unlike line segments, which have defined starting and ending points, a straight line has an infinite length and continues indefinitely without termination.
A line.
a line
line
A line
That's the definition of a "line".
line
A line.
A straight line without any defined end points
a line
line
It would be a horizontal straight line, extending without end in both directions.
If you meant one direction, then it is a ray.
It is a tangent line
it is called a line imma 7th grader yall
"Tout droit" is French for "straight ahead." It is commonly used to give directions or indicate that something is directly ahead without any turns.