semidiurnal

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

adjective

1. pertaining to, consisting of, or accomplished in half a day.
2. occurring every 12 hours or twice each day.

semidiurnal

/ ˌsɛmɪdaɪˈɜːnəl /

adjective

1. of or continuing during half a day
2. occurring every 12 hours

Word History and Origins

Origin of semidiurnal¹

First recorded in 1585–95; semi- + diurnal

Example Sentences

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

From Project Gutenberg

As a consequence the semidiurnal portion of the tide wave in these regions is almost wholly derived from the tides in the Atlantic Ocean.

From Project Gutenberg