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

It's made with refrigerated cheese tortellini and chicken breast, and thickened with tangy cream cheese for a hearty and satisfying meal that's also full of veggies. —Lizzy Briskin, Better Homes & Gardens, 19 Apr. 2026

For such people, a seemingly harmless bite of bread, pasta, or even a sauce thickened behind the scenes can trigger bloating, fatigue or lingering digestive distress. —Daryl Austin, USA Today, 19 Apr. 2026

Green enchilada sauce and a poblano chiles add the right amount of heat while the mashed Great Northern beans thicken the broth—no dairy needed. —Amanda Favazza, Southern Living, 15 Apr. 2026

Simmer until thickened to a syrup, 3 to 5 minutes. —The New York Times News Service Syndicate, San Diego Union-Tribune, 15 Apr. 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