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

To help prevent overdosing liquid or powdered formulas, use a permanent marker to make clear measurement guidelines on caps. —Mary Marlowe Leverette, Southern Living, 27 Nov. 2025

In the clip, Izabelle is happily coloring using dot markers. —Daniella Gray, MSNBC Newsweek, 27 Nov. 2025

Gap Leopard Brown Modern Turtleneck Bold, flashy leopard print is an Italian style marker seen on everyone from Sofia Loren to Kim Kardashian in Dolce & Gabbana. —Nneya Richards, Travel + Leisure, 26 Nov. 2025

Observational studies show an association between greater green tea consumption and lower circulating ferritin levels, a marker of iron storage levels. —Amy Brownstein, Verywell Health, 26 Nov. 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