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

South Carolina right-handed pitcher Jori Heard allowed only one hit through two innings, keeping UCLA’s potent bats relatively quiet.

From Los Angeles Times • May 18, 2026

An infection with Bundibugyo virus can occur when someone comes in contact with infected bats or primates, according to the WHO.

From MarketWatch • May 17, 2026

Ebola, believed to have originated in bats, is a deadly viral disease spread through direct contact with bodily fluids.

From Barron's • May 16, 2026

We traveled at great speed and blind as bats.

From "Secrets at Sea" by Richard Peck

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