as in flibbertigibbets
a silly flighty person
in a medical situation of this seriousness we don't need some rattlebrain running around in a panic
Synonyms & Similar Words
Relevance
Antonyms & Near Antonyms
Example Sentences
Recent Examples of Synonyms for rattlebrains
Noun
-
His strict and meticulous methodologies taught some of the smartest people on the planet how to behave like complete idiots, paving the way for a new generation of red-nosed fools to pratfall onto the stage.—
Fran Hoepfner,
Vulture,
10 Feb. 2026 -
Sadly, OpenAI plays us for fools.—
Jim Cramer,
CNBC,
8 Feb. 2026
Noun
-
Five young men in an ATV were seen repeatedly running over 30 Egyptian geese off SW 120th avenue back in December 2024.—
Joan Murray,
CBS News,
10 Feb. 2026
-
According to federal officials, Canadian geese are protected under the Migratory Bird Treaty Act.—
Sean Neumann,
PEOPLE,
28 Jan. 2026
Noun
-
Canada geese are protected, as well as most other geese, swans, ducks, cranes, cuckoos, hummingbirds, doves and flamingos.—
Kyle Werner,
Des Moines Register,
27 Jan. 2026
-
Brood parasites such as cuckoos lay their eggs in other birds’ nests, tricking the hosts into caring for their offspring at the expense of their own.—
Matthew Martin,
semafor.com,
6 Oct. 2025
Examples are automatically compiled from online sources to
show current usage.
Read More
Opinions expressed in the examples do not represent those of Merriam-Webster or its editors.
Send us feedback.
Cite this Entry
“Rattlebrains.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/rattlebrains. Accessed 19 Feb. 2026.
Copy CitationLove words? Need even more definitions?
Merriam-Webster unabridged
