break·through
ˈbrāk-ˌthrü 
plural breakthroughs
1
a
: a sudden advance especially in knowledge or technique
a medical breakthrough
b
: a person's first notable success
—often used before another noun
a breakthrough novel
the actress's breakthrough performance
2
a
: an act or instance of moving through or beyond an obstacle
a breakthrough in the talks between the region's leaders
a breakthrough agreement
b
: an instance of passing through a barrier or protection
The ice under the surface begins to deteriorate, increasing the risk of breakthroughs.—
Vicki Winger
Vicki Winger
specifically, medical
: infection occurring in someone who is fully vaccinated against an infectious agent
A vaccine breakthrough occurs when a person tests positive for COVID-19 two weeks after being fully vaccinated against the disease … —David Rasbach
—often used before another noun David Rasbach Two other CDC studies of breakthrough cases at nursing homes showed the vaccines protected residents, even when the virus spread through the homes. —Maura Dolan
Maura Dolan … the academy recently recommended that children receive two doses of the chicken pox vaccine, rather than just one, because the additional dose bolsters immunity and may help reduce breakthrough infection. —Maria Raven
Maria Raven 3
warfare
: an offensive military assault that penetrates and carries beyond a defensive line
broke through; broken through; breaking through; breaks through
: to make a breakthrough
Synonyms
Examples of breakthrough in a Sentence
Noun
Researchers say they have made a major breakthrough in cancer treatment.
The police have announced a breakthrough in the murder case.
This job could be the breakthrough she's been waiting for.
Recent Examples on the Web
Nick Penzenstadler, USA TODAY, 10 Dec. 2024
The breakthrough came in 2022 when the sheriff’s dept. received a grant from the State Attorney General’s Office enabling them to send the DNA sample to Parabons NanoLab in Virginia for genetic genealogy testing.
—Clare Fisher, People.com, 9 Dec. 2024
Ew Staff, EW.com, 5 Dec. 2024
Thousands of citizens and journalists crowded outside the gates of the National Assembly, while a phalanx of military special-forces officers, toting rifles, broke through windows to get inside.
—E. Tammy Kim, The New Yorker, 4 Dec. 2024
See all Example Sentences for breakthrough 
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Noun
The breakthrough came on the sixth day of a massive search involving the NYPD, the FBI and other agencies.
—Nick Penzenstadler, USA TODAY, 10 Dec. 2024
The breakthrough came in 2022 when the sheriff’s dept. received a grant from the State Attorney General’s Office enabling them to send the DNA sample to Parabons NanoLab in Virginia for genetic genealogy testing.
—Clare Fisher, People.com, 9 Dec. 2024
Verb
And yet, a handful of shows managed to break through the chaos with specific episodes that had everyone talking.
—Ew Staff, EW.com, 5 Dec. 2024
Thousands of citizens and journalists crowded outside the gates of the National Assembly, while a phalanx of military special-forces officers, toting rifles, broke through windows to get inside.
—E. Tammy Kim, The New Yorker, 4 Dec. 2024
See all Example Sentences for breakthrough
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Cite this Entry
“Breakthrough.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/breakthrough. Accessed 23 Dec. 2024.
Copy CitationKids Definition
breakthrough
noun
break·through
ˈbrāk-ˌthrü
: a sudden advance in knowledge or technique
a breakthrough in medical science
Medical Definition
breakthrough
noun
break·through
ˈbrāk-ˌthrü
: infection occurring in someone who is fully vaccinated against an infectious agent
—often used before another noun
breakthrough infections
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