plural breakthroughs
1
: a sudden increase in knowledge, understanding, etc. : an important discovery that happens after trying for a long time to understand or explain something
Researchers say they have made/achieved a major breakthrough in cancer treatment.
a scientific breakthrough
The police have announced a breakthrough in the murder case.
—sometimes used before another nounbreakthrough ideas/products
2
: a person's first important success
This job could be the breakthrough she's been waiting for.
—sometimes used before another nouna breakthrough performance/role/album
Cite this Entry
“Breakthrough.” Merriam-Webster.com Simple Definition, Merriam-Webster, https://www.merriam-webster.com/simple/breakthrough. Accessed 15 Jun. 2026.
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