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

The figs would cook until their tough outer skin softened and some began to burst open to gently ooze their seedy pulp, thickening the mixture into a grainy, molasses-brown syrup, while other figs remained whole, their thick stems still attached. —Claude Barilleaux, Christian Science Monitor, 9 Apr. 2025

Whisk together pudding and pie filling, milk, and coconut extract in a large bowl until smooth and starting to thicken, about 2 minutes. —Kimberly Holland, Southern Living, 7 Apr. 2025

Formulated with organic amla and rice protein and proven to thicken hair by 11% (per the brand), the volumizing foam will create fuller, all-day voluminous curls. —Natasha Marsh, Allure, 7 Apr. 2025

When the semolina has thickened the soup to a loose porridge-like consistently, turn off the heat. —Vicky Hallett, NPR, 1 Apr. 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