haystack

noun

hay·​stack ˈhā-ˌstak 

1

: a stack of hay

2

: a vertical standing wave in turbulent river waters

Examples of haystack in a Sentence

Recent Examples on the Web

This was the kind of needle in a haystack doctors hoped to find when health systems first started experimenting with generative AI tools like ChatEHR to search and synthesize patients’ health records. — Katie Palmer, STAT, 20 Aug. 2026

In other words, the porcini’s range is extremely broad, which makes finding them a needle-in-haystack situation. — Katie Hill, Outdoor Life, 6 Aug. 2026

Boasting nearly 10,000 five-star reviews, this classic metal bed frame is a needle in Amazon’s furniture haystack. — Nashia Baker, Architectural Digest, 16 July 2026

How an audience discovers that needle in the haystack requires research rigor requiring access to a multiplicity of data streams. — Frank Racioppi, Forbes.com, 7 July 2026

Word History

First Known Use

15th century, in the meaning defined at sense 1

Phrases Containing haystack

• a needle in a haystack

Rhymes for haystack

• aback
• attack
• backpack
• backtrack
• bareback
• blackjack
• brownback
• buyback
• callback
• cognac
• comeback
• cutback

Kids Definition

haystack

noun

hay·​stack -ˌstak 

: a stack of hay