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

• label
• tag
• ticket

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

It’s also being viewed as a marker of the Trump administration’s attempts to detain and deport visa holders who protested on college campuses. —Michael Dorgan, FOXNews.com, 25 Apr. 2025

New polls show Trump’s approval slipping In less than a week, President Donald Trump will meet the 100-day marker of his second term as president. —Rebecca Morin, USA Today, 25 Apr. 2025

The first 100 days of a president’s time in office is a traditional marker for how the president plans to move through the next four years of their administration. —Lauren Irwin, The Hill, 24 Apr. 2025

Their inflammatory markers were monitored through blood, urine, and stool samples, and colon polyps were examined through high-definition colonoscopies. —Thomas G. Moukawsher, MSNBC Newsweek, 24 Apr. 2025

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