blocker
Americannoun
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a person or thing that blocks.
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Football. a player whose assignment or special skill is blocking.
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Biochemistry. a substance that inhibits the physiological action of another substance, as the beta blocker propranolol that interferes with neurotransmitters in the sympathetic nervous system.
noun
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a person or thing that acts as a block
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physiol an agent that blocks a physiological function, such as the transport of an ion across an ion channel
Etymology
Origin of blocker
Middle English word dating back to 1200–50; see origin at block, -er 1
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.
Miller is durable and a particularly adept pass blocker.
From Los Angeles Times • Mar. 17, 2026
It might — though there’s a major potential blocker I’ll get to in a moment.
From MarketWatch • Feb. 10, 2026
For those at risk of preterm labor, a PIEZO1 blocker, if developed, could work alongside current medications that relax uterine muscle by limiting calcium entry into cells.
From Science Daily • Jan. 13, 2026
Among some tech leaders it's seen as, at best, a blocker to smoother digital workflows and AI, at worst, an accident waiting to happen.
From BBC • Jan. 8, 2026
He could hit like a locomotive and was a devastating blocker.
From "October Sky" by Homer Hickam
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
