horizontal line

American  

[hawr-uh-zahn-tuhl lahyn] / ˌhɔr əˈzɑn təl ˈlaɪn /

noun

plural

horizontal lines

1. a line that is parallel to the base of a surface or plane. Compare vertical line.

2. Mathematics. a line whose points all have the same vertical coordinate.

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Example Sentences

If gold was an effective hedge against inflation — if it protected your purchasing power — that chart would be a reasonably stable horizontal line from left to right.

From MarketWatch • Oct. 14, 2025

Close inspection also shows a faint horizontal line bisecting each Milky Way star, which is caused by light bending around a support strut of the telescope’s secondary mirror.

From Scientific American • Nov. 3, 2023

After reading about the science of math movement, she became more explicit about things that she assumed students understood, like how the horizontal line in a fraction means the same thing as a division sign.

From Seattle Times • Sep. 12, 2023

“Once you grasp the vowels, you can get your tongue around most of the words — long sounds, short sounds, the macron,” the horizontal line above a vowel that indicates a stressed syllable, he said.

From New York Times • Jul. 16, 2023

I draw a horizontal line for the ground and a daisy popping up next to the tree.

From "Speak" by Laurie Halse Anderson