[ sem-ee-an-yoo-uhl, sem-ahy- ]
See synonyms for semiannual on
  1. Also semiyearly . occurring, done, or published every half year or twice a year; biannual.

  2. lasting for half a year: a semiannual plant.

Origin of semiannual

First recorded in 1785–95; semi- + annual

confusables note For semiannual

See bi-1.

Other words from semiannual

  • sem·i·an·nu·al·ly, adverb

Words that may be confused with semiannual Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use semiannual in a sentence

  • I am held accountable to the Secretary of the Treasury semiannually for the manner in which the appropriation has been expended.

    Red Men and White | Owen Wister
  • He had established a branch of his gigantic business there and himself rolled semiannually from coast to coast in his private car.

    Play the Game! | Ruth Comfort Mitchell
  • Weekly or monthly or yearly, sometimes semiannually, and so forth.

    Warren Commission (8 of 26): Hearings Vol. VIII (of 15) | The President's Commission on the Assassination of President Kennedy
  • The cockroach is born on the fust ov May and the fust ov November semiannually, and is reddy for use in fifteen days from date.

British Dictionary definitions for semiannual


/ (ˌsɛmɪˈænjʊəl) /

  1. occurring every half-year

  2. lasting for half a year

Derived forms of semiannual

  • semiannually, 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