semidiurnal
(-dī ʉr′nəl)
adjective
- of, lasting, or performed in half a day
- occurring twice a day, as the tides
See semidiurnal in American Heritage Dictionary 4
adjective- Of, relating to, occurring, or performed during half a day.
- Occurring or coming approximately once every 12 hours, as the tides.
- Of or relating to the arc described by a celestial body between its meridian passage and its points of rising or setting.
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