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

The researchers found strong deposits of 3-nitrotyrosine, a molecular marker associated with cellular damage caused by reactive oxygen species. — Melissa Cristina Márquez, Forbes.com, 1 Aug. 2026

Beyond new stores and designs, a better marker of Polène’s evolution for the CEO is how the company is doubling down on production processes, quality control and services. — Lily Templeton, Footwear News, 31 July 2026

Interstate 435 between mile markers 31 and 32, and between mile markers 41 and 45. — Kansas City Star Weather Bot, Kansas City Star, 31 July 2026

That changed in 2014, when India’s Supreme Court recognized transgender people and affirmed their right to determine their own legal gender markers – no government or medical sign-off required. — Aakash Hassan, Christian Science Monitor, 31 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