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

Homeland Security Secretary Markwayne Mullin said the Coast Guard was supporting state and local responders near mile marker 96 on the Mississippi River. — Stepheny Price, FOXNews.com, 13 Nov. 2026

On the counter are rows of pills in cups, inhalers, and, next to them, Old Spice deodorant, each with the name of the older children in permanent marker. — Rebecca Jennings, Vulture, 12 Nov. 2026

An effective but ‘not perfect’ tool The PSA’s role as a marker to help screening for prostate cancer was discovered in the 1970s. — Jacqueline Howard, CNN Money, 12 Nov. 2026

Chopper 3 was over the scene where crime scene tape surrounded a white car, with several evidence markers near the driver's side. — Frederick Sutton Sinclair, CBS News, 12 Nov. 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