curdle

American  

[kur-dl] / ˈkɜr dl /

verb (used with or without object)

curdled, curdling

1. to change into curd; coagulate; congeal.

2. to spoil; turn sour.

3. to go wrong; turn bad or fail.

   Their friendship began to curdle as soon as they became business rivals.

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idioms

1. curdle the / one's blood, to fill a person with horror or fear; terrify.

   a scream that curdled the blood.

curdle British  

/ ˈkɜːdəl /

verb

1. to turn or cause to turn into curd

2. to fill someone with fear

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Other Word Forms

• curdler noun
• noncurdling adjective
• uncurdled adjective
• uncurdling adjective

Etymology

Origin of curdle

First recorded in 1580–90; curd + -le

Example Sentences

Piercing and horrible, the screaming is pitched to curdle the listener’s blood but not, in this instance, to overwhelm the voice of the narrator.

From The Wall Street Journal • Dec. 19, 2025

As co-written by Baumbach and Emily Mortimer, the reunion between the two former acting buddies starts warm but quickly begins to curdle.

From Los Angeles Times • Nov. 7, 2025

That could cause the cream to curdle, so use a double boiler.

From Salon • Nov. 30, 2023

Don’t be concerned if it starts to curdle — that’s normal.

From Washington Post • Sep. 2, 2022

Tina shrieks loud enough to curdle the blood of a ghost.

From "How It Went Down" by Kekla Magoon