bats

American

[bats] / bæts /

adjective

Slang.

insane; crazy.

He's gone bats.

bats British

/ bæts /

adjective

informal crazy; very eccentric

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Etymology

Origin of bats

First recorded in 1915–20; see origin at bat ², -s ³

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

Scientists believe African fruit bats may be the source of the viruses that cause Ebola, according to the CDC.

From The Wall Street Journal • May 18, 2026

Ebola, believed to have originated in bats, can cause severe bleeding and organ failure.

From Barron's • May 17, 2026

Most Ebola spillover events, which is when a virus like Ebola is transmitted to humans, occur in miners working deep in caves where bats live.

From MarketWatch • May 17, 2026

In Life on Earth, his team filmed bats in a wind-tunnel.

From BBC • May 9, 2026

Miig had told us once about how bats moved.

From "The Marrow Thieves" by Cherie Dimaline

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023