semidiurnal

[sem-ee-dahy-ur-nl, sem-ahy-]

adjective

pertaining to, consisting of, or accomplished in half a day.

occurring every 12 hours or twice each day.

Origin of semidiurnal

First recorded in 1585–95; semi- + diurnal

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for semidiurnal

Historical Examples of semidiurnal

The semidiurnal tidal forces vanish at the Pole and are very small over the entire Arctic Ocean.
The North Pole
Robert E. Peary

British Dictionary definitions for semidiurnal

semidiurnal

adjective

of or continuing during half a day

occurring every 12 hours

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