haystack

American  

[hey-stak] / ˈheɪˌstæk /

noun

haystacks plural

1. a stack of hay with a conical or ridged top, built up in the mowed field so as to prevent the accumulation of moisture and promote drying.

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haystack British  

/ ˈheɪˌrɪk, ˈheɪˌstæk /

noun

1. a large pile of hay, esp one built in the open air and covered with thatch

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haystack Idioms  

1. see needle in a haystack.

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Other Word Forms

Noun Inflected Forms

• haystacks
  plural

Etymology

Origin of haystack

1425–75; late Middle English. See hay, stack

Explanation

A haystack is a pile or bundle of hay. On farms, after hay has been cut, it's formed into haystacks until being fed to farm animals. Haystacks come in different shapes and sizes, including piles of rectangular blocks of hay; rounded bales; and pointed piles of hay. These haystacks are all packed tightly, and they're often covered to protect them from the rain. You've probably heard the phrase "a needle in a haystack," an idiom that's used when a search is on for some impossibly tiny thing that's lost.

Example Sentences

"Searching for anything in it is like hunting for a needle in a haystack," he says.

From BBC • Jun. 27, 2026

That kind of return is like finding a needle—or a pin—in a haystack.

From Barron's • Jun. 18, 2026

The best place to hide needles is in a haystack.

From MarketWatch • Jun. 10, 2026

“You can kind of imagine that all of Southern California is like a haystack right now, waiting for a single spark,” he said.

From Los Angeles Times • May 20, 2026

He stood up, removed his psychedelic headband from that haystack of hair, and bowed solemnly.

From "Schooled" by Gordon Korman