Vis fluminis
Defined in 2 dictionaries — Ballentine's (1916), Black's (1910)
Ballentine's Law Dictionary
James A. Ballentine · 1916
The force of the current.
Black's Law Dictionary
Henry Campbell Black, M.A. · 1910
In the civil law. The force of a river; the force exerted by a stream or current; water-power.
Defined under Vis in Black's Law Dictionary.