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

Maybe listening to this song will encourage your toddler to pick up crayons or markers and create some adventures of their own. — Parents, 3 July 2026

Healthy cells carry markers that identify them as part of the body, while foreign or damaged entities are treated as candidates for containment or destruction. — Abhik Biswas, Forbes.com, 2 July 2026

At the same time, her eyes were free of the ultimate Millennial marker, winged liner, and colored with a melting pot of brown, bronze and dusty gray shadow, visible in her waterline, too. — Kaleigh Werner, Footwear News, 2 July 2026

Telomeres, which sit at the ends of chromosomes to protect genetic material, shorten with age and are a reliable marker of biological aging. — New Atlas, 2 July 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