[sem-ee-aw-tuh-mat-ik, sem-ahy-]


partly automatic.
(of a firearm) automatically ejecting the cartridge case of a fired shot and loading the next cartridge from the magazine but requiring a squeeze of the trigger to fire each individual shot.


a self-loading rifle or other firearm.

Origin of semiautomatic

First recorded in 1890–95; semi- + automatic
Related formssem·i·au·to·mat·i·cal·ly, adverb Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for semi-automatic

Contemporary Examples of semi-automatic

Historical Examples of semi-automatic

  • For work which is automatic or semi-automatic, boys or girls may be employed.

  • Then try to play the two hands together in a sort of semi-automatic way.

    Piano Playing

    Josef Hofmann

  • They occupy a semi-automatic middle ground between conscious and subconscious activities.

    The Trained Memory

    Warren Hilton

  • The vast McCormick City has its human side, too, in spite of all its noise and semi-automatic machinery.

    Cyrus Hall McCormick

    Herbert Newton Casson

  • Glass is blown by three methods: hand-blowing, semi-automatic blowing, and automatic blowing.

British Dictionary definitions for semi-automatic



partly automatic
(of a firearm) self-loading but firing only one shot at each pull of the triggerCompare automatic (def. 5)


a semiautomatic firearm
Derived Formssemiautomatically, adverb
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 semi-automatic

1853, from semi- + automatic (adj.). In reference to firearms, 1889.

Online Etymology Dictionary, © 2010 Douglas Harper