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

One of the best actors working today, Coon essentially plays two different sides of Rita with astonishing range across these chronologies, portraying the past and the present of her character through distinctive markers. — Tomris Laffly, Variety, 5 Sep. 2026

The bottom line, however, is that psychiatry and psychology should not compete over markers. — Torie Bosch, STAT, 5 Sep. 2026

The Wood Chucks woodworking group has created benches and plant markers for the paths, among other projects. — Erickson Senior Living, Charlotte Observer, 4 Sep. 2026

Whole grains tend to be among the best anti-inflammatory carbohydrates because of their nutrient composition and association with lower levels of inflammatory markers. — Amy Brownstein, Verywell Health, 4 Sep. 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