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

Taking note of these markers can help women make lifestyle adjustments, such as adopting a heart-healthy diet, increasing physical activity, or reducing alcohol consumption. —Alexa Mikhail, Flow Space, 4 Sep. 2025

Certain cancers The antioxidants in oranges and orange juice may have properties that lower inflammatory markers in the body. —Carrie Madormo, Verywell Health, 4 Sep. 2025

This includes the following highways, Route 79 between mile markers 92 and 128. —Stephen Harding, AZCentral.com, 4 Sep. 2025

In distribution terms, the Greek deal is a marker as NBCU attempts to get the show back into international markets and establish production bases that can be used to efficiently make multiple versions. —Stewart Clarke, Deadline, 4 Sep. 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