[ 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

Middle English word dating back to 1200–50; see origin at block, -er1 Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for blocker

British Dictionary definitions for blocker


/ (ˈblɒkə) /


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

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