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

The novella lacks the temporal markers that indicate how much time has passed between episodes and exhibits an abundance of characters with ruptured psyches. —JSTOR Daily, 30 Oct. 2025

By enabling or disabling layers (layout, markers, heat map) and adjusting layer opacity, users get a clear, customizable view of what’s happening—and where to look next. —IEEE Spectrum, 30 Oct. 2025

Following the crash, the Kendall County Sheriff’s Office announced on Facebook that the westbound lane of I-10 near the 534-mile marker was closed and that traffic was being diverted. —Sam Gillette, PEOPLE, 29 Oct. 2025

Wear neutral clothes underneath, and use face paint or markers to draw a digital mouth or screen for an instant retro robot. —Elizabeth Fogarty, Better Homes & Gardens, 28 Oct. 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