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

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

Dial options include matte black, tropical brown, and vintage navy, all featuring creamy Super-LumiNova GL old radium markers designed to evoke the faded lume of historic tool watches. —Matthew Catellier, Forbes.com, 30 July 2025

The goal is to boost the immune response against cancer-specific markers (like HER2 or mammaglobin-A), so the body can find and destroy any remaining cancer cells. —Lauryn Higgins, Flow Space, 29 July 2025

Lunch boxes, markers, notebooks and notebook filler paper. —Howard Cohen, Miami Herald, 29 July 2025

Failing to repay a casino marker is treated as writing a bad check under Nevada law, and not paying a marker worth more than $1,200 can indeed result in felony charges. —Joseph Wilkinson, New York Daily News, 28 July 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