thicken

verb

thick·​en ˈthi-kən 

thickened; thickening ˈthi-kə-niŋ 

ˈthik-

intransitive verb

1

a

: to become dense

the mist thickened

b

: to become concentrated in numbers, mass, or frequency

2

: to grow blurred or obscure

3

: to grow broader or bulkier

4

: to grow complicated or keen

the plot thickens

transitive verb

1

a

: to make thick, dense, or viscous in consistency

thicken gravy with flour

b

: to make close or compact

2

: to increase the depth or diameter of

3

: to make inarticulate : blur

alcohol thickened his speech

thickener

ˈthi-kə-nər 

ˈthik-

noun

Examples of thicken in a Sentence

I thickened the gravy with flour.

When the mixture thickens, add the remaining ingredients.

The fog thickened when night fell.

Recent Examples on the Web

Reduce heat to medium-low; cook, stirring occasionally, until thickened and grits are tender, 15 to 20 minutes. —Melinda Salchert, Southern Living, 27 Oct. 2025

The king would melt bars of chocolate with water in a 1-to-1 ratio, then thicken the mixture gently over low heat, slowly whisking in an egg yolk to give the drink a smooth richness. —Aleksandra Crapanzano, The Atlantic, 27 Oct. 2025

The sauce, a velvety broth, is a mixture of natural juices and stewing ingredients, sometimes thickened with flour. —Cathy Thomas, Oc Register, 27 Oct. 2025

Add a hearty grain to thicken the broth. —Lynda Balslev, Mercury News, 24 Oct. 2025

Word History

First Known Use

14th century, in the meaning defined at intransitive sense 1a

Rhymes for thicken

• chicken
• likin
• quicken
• sicken
• stricken
• indican

Kids Definition

thicken

verb

thick·​en ˈthik-ən 

thickened; thickening -(ə-)niŋ 

1

: to make or become thick, dense, or viscous

thicken gravy with flour

2

: to become complicated

the plot thickens

thickener

-(ə-)nər 

noun