[ blok-er ]

  1. a person or thing that blocks.

  2. Football. a player whose assignment or special skill is blocking.

  1. 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

Middle English word dating back to 1200–50; see origin at block, -er1

Words Nearby blocker Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use blocker in a sentence

British Dictionary definitions for blocker


/ (ˈblɒkə) /

  1. a person or thing that acts as a block

  2. 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