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

Note: if the mixture thickens more than desired over time, add a little water or beef broth. —Robin Miller, AZCentral.com, 10 July 2025

It gets topped with crispy fries smothered in cheddar cheese curds and our homemade lobster gravy, which is made by concentrating our shellfish stock, thickening it with a roux, and fortifying it with our lobster bisque. —Aly Walansky, Forbes.com, 5 July 2025

Immediately pour pudding evenly over cake (pudding will thicken quickly), making sure to fill holes. —Kimberly Holland, Southern Living, 23 June 2025

Boil while stirring until the sugar is dissolved and the mixture thickens. —Lillian Ali, Smithsonian Magazine, 17 June 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