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

Bring to a simmer, reduce the heat to low, and cook, stirring occasionally, until the chili is slightly thickened and the beans are flavorful, about 10 minutes. —Kate Williams, AJC.com, 16 Mar. 2026

Once again, the plot is sure to thicken from here. —Andy Andersen, Vulture, 16 Mar. 2026

Once thickened to your liking, transfer to a container and add toppings if desired. —Kathleen Ferraro, Verywell Health, 12 Mar. 2026

Bring to a simmer, and cook, stirring constantly, until sauce has slightly thickened, about 1 minute. —John Metcalfe, Mercury News, 11 Mar. 2026

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