adjective / adverb
straight
STRAYT/strˈeɪt/
Without deviation from a direct course.
The wooden rod is straight, unlike the curved branch beside it.

Etymology
Straight comes from a participle of streccan, “stretch,” and originally meant “stretched.” A string pulled taut supplies the image connecting stretching with a line that does not bend or curve.
In context
I see the stone descend in a straight line a pedestrian who observes the misdeed from the foot path notices that the Stone Falls to Earth in a parabolic curve
More examples
- Keep walking straight until you reach the next intersection.
- Let me get the facts straight before I answer.
- She works five straight days before taking a day off.
Forms
straight · straighter · straightest
straighten verb — To make or become free of bends.
straightness noun — The quality of being free of bends.