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[blok-er] /ˈblɒk ər/
a person or thing that blocks.
Football. a player whose assignment or special skill is blocking.
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.
Origin of blocker
1200-50; Middle English; see block, -er1 Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2015.
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Examples from the web for blocker
  • Propranolol is a beta-blocker, so it blocks the action of adrenaline.
  • Propranolol, a beta blocker drug, has no beneficial effect on the symptoms of hangover.
  • They also know that capsaicin is an effective blocker.
  • Yes, so make sure your pop-up blocker is configured to allow them.
  • It is also being evaluated in combination with selective alpha-blocker drugs.
  • When you run the single-wing, you have an extra blocker.
  • Has size and strength to make him good drive blocker.
  • Excellent rebounder and shot-blocker but his offensive game is lacking.
  • Is an above-average blocker whose receiving skills have improved greatly since his first few seasons.
  • He still has a lot to learn as a blocker and route-runner, but his size and eye-popping athletic ability are undeniable.
British Dictionary definitions for blocker


a person or thing that acts as a block
(physiol) an agent that blocks a physiological function, such as the transport of an ion across an ion channel
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
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Word Origin and History for blocker

c.1400 of a tool, c.1600 of a person, agent noun from block (v.). U.S. football sense from 1914.

Online Etymology Dictionary, © 2010 Douglas Harper
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