vertical line

noun

: a line perpendicular to a surface or to another line considered as a base: such as

a

: a line perpendicular to the horizon

b

: a line parallel to the sides of a page or sheet as distinguished from a horizontal line

c

: the direction of a plumb line : a line normal to the surface of still water

Love words?

You must — there are over 200,000 words in our free online dictionary, but you are looking for one that’s only in the Merriam-Webster Unabridged Dictionary.

Start your free trial today and get unlimited access to America's largest dictionary, with:

• More than 250,000 words that aren't in our free dictionary
• Expanded definitions, etymologies, and usage notes
• Advanced search features
• Ad free!