Current use

This river flows north from the mountains through a large part of the Velkan Barony, allowing good trade to occur on it. The wide river, and high banks make them ideal locations for castles and defenses throughout the ages.

History
Originally referred to as "Flod zu ferd nul" in the Jotun language, which roughly translates to "The River that Journeys to Nothing"
ie the calm seas, where there are no stones, hills, and barely the weather for storms. Nothing of value to giants.

Since then the phrase slowly devolved, being misheard, miscarved, and misread by giants, dwarves, and humans.

Likely Etymology: Flod-zu-ferd-nul -> Flodzuferdnul -> Flomduferdnul -> Flunterferdnul -> Flunterfel -> Floonterfel River

However, after the Age of Humans came, they began calling it the Gurakkek River after Unknown, the River Serpent by any who lived off of the river, or feared it.

Nowadays you may hear either name, Floonterfel has slowly come into fashion again by those siding with, or at least feigning respect of, the Giants.