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

But his playing partner and marker, Brandon Rice, put him down for a 4 on the 16th, but a 5 on the 17th. — Ian Miller Outkick, FOXNews.com, 9 Oct. 2026

Patients with detectable ctDNA at six months were 30 times more likely to progress in their disease during the study, suggesting ctDNA was a marker of potential progression. — Allessandra Dicorato, STAT, 8 Oct. 2026

On the flip side, other studies have found that front-loading calories earlier in the day may contribute to weight loss and improvements in metabolic health markers. — Jamie Ducharme, HEALTH, 7 Oct. 2026

Still, that legal settlement helped make the 2030-31 a significant marker. — ABC News, 6 Oct. 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