The term 'semimonthly tide' refers to a type of tide that occurs twice a month. The term is derived from the Latin word 'NEAP', which means twice a month. A semimonthly tide is characterized by two high and two low tides each month, with the highest and lowest tides occurring at the same time each month. This type of tide is most common in coastal areas, where the moon's gravitational pull has a greater effect on the ocean's water levels.