king tide
n.— «During a King Tide, which is what the islanders call the highest tides of the year, waves rolling off the ocean can have a devastating effect.…A typical high tide reaches about two-and-a-half metres, while a King Tide like this can be more than three metres.» —“Tuvalu struggles to hold back tide” by David Shukman in Tuvalu BBC News (United Kingdom) Jan. 22, 2008. (source: Double-Tongued Dictionary)