Question: What is the river 3 mi north-west of Gainsborough said to take its name from?
Related documents: [0]  [DOC] The Trent Aegir, also known as the Eagre, is a tidal bore on the River Trent in England. At certain times of the year, the lower tidal reaches of the Trent experience a moderately large bore (up to five feet (1.5m) high). It is said to take its name from "Ægir", the Norse god of the ocean, although this is disputed. [END] 
[1]  [DOC] East Stockwith is a village within the civil parish of East Stockwith, in the West Lindsey district of Lincolnshire, England. It lies on the River Trent, 3 mi north-west of Gainsborough. The River Trent Aegir, a tidal bore, reaches the village. In 2001 it had a total resident population of 209, increasing to 314 at the 2011 census. [END] 
Answer: 
the Norse god of the ocean
the Norse god of the ocean