aegir aegir /ˈeɪɡɪr/

noun

1. [Non-standard] A high wave (often dangerous) caused by tidal flow (as by colliding tidal currents or in a narrow estuary)  ( aegir [Non-standard] , bore , eager [Dialect, UK] , eagre [Dialect, UK] , tidal bore )
   a high wave (often dangerous) caused by tidal flow (as by colliding tidal currents or in a narrow estuary)