marker

noun

mark·​er ˈmär-kər 

1

: one that marks

2

: something used for marking: such as

a

: a type of felt tip pen that makes wide lines

drew a tree with green and brown markers

used a permanent marker to label the boxes

b

: any of various sewing devices for making or indicating guidelines

a pin marker for hemlines

3

: score sense 7

specifically : run

4

: promissory note, iou

5

: something that serves to identify, predict, or characterize: such as

a

: biomarker

b

: genetic marker

Synonyms of marker

• label

Examples of marker in a Sentence

A person's accent can be a marker of social class.

the markers on the rock and mineral specimens were old and faded

Recent Examples on the Web

The bond will sit in the market as a marker, a sign of where confidence stood at the start of 2026, when investors were willing to lend to a private technology company for a century at a time when the world's democracies struggle to issue debt beyond fifty years. —Dara-Abasi Ita, Forbes.com, 18 June 2026

From the official starting point in Chicago to its dramatic end marker at Lincoln and Olympic boulevards in Santa Monica on the Pacific Ocean, here are some of the best attractions to visit on an epic Route 66 road trip. —Elizabeth Rhodes, Travel + Leisure, 18 June 2026

According to fire officials, the Ko Fire was burning near Colorado Highway 115 at mile marker 20 in the area of Fremont County Road F45. —Jennifer McRae, CBS News, 18 June 2026

This includes Interstate 95 in North Carolina between mile markers 20 and 26. —Nc Weather Bot, Charlotte Observer, 18 June 2026

Word History

First Known Use

15th century, in the meaning defined at sense 1

Phrases Containing marker

• genetic marker

Rhymes for marker

• barker
• darker
• starker
• biomarker

Kids Definition

marker

noun

mark·​er ˈmär-kər 

1

: one that marks

2

: something used for marking

Medical Definition

marker

noun

mark·​er ˈmär-kər 

: something that serves to identify, predict, or characterize

a surface marker on a cell that acts as an antigen

: as

a

: biomarker

The recent discovery of a serological marker for the hepatitis C virus has greatly improved diagnostic accuracy for this form of hepatitis.

—Gary P. Wormser, letter in The Journal of the American Medical Association

b

: genetic marker

The idea in genetic linkage analysis is to see if any particular marker, which serves as a signpost for a specific region of a chromosome, is consistently inherited along with the disease …

—Leslie Roberts, Science

called also marker gene