From the department of Mayenne (Normandy), at Juvigné, where the Vilaine takes its spring (source) till its estuary, near Pénestin (Brittany), the geography of the river allows number of play on words. The word itself of "vilaine" means "nasty, ugly" and is used in the feminine gender...
Some names (towns, places) may give rise to puns : Rennes souding like "reine" (queen) with a legend of Vilaine baths in this town affording beauty to women ; Redon (part of this word going with "eiderdown"), in link with the fact that, in french, a river which overflows its banks is said to "get off her bed" ; the bridge of Cran (meaning also pluck, courage) ; Pénestin containing the word "éteint" meaning extincted, switched off...
A short extract of a traditional breton dance is included in the song, at a moment wich represents the youth of the river. It recalls us the happy and fertile period of the celtic circle "Er Lann Eur" we attended to.
Then the river will leave the peaceful and quiet stream we had imagined.
Later, "water has been flowing under the bridges" (time has passed) and the banks will undwind a time of wisdom and serenity.
Let's go back to the spring when the river mixes its water with the sea salt. Several etymologic sources have led to the name of Vilaine (latin etymology of Visnonia, among others). Let us opt for "ar Gwilen", in breton language : the river with mills (if we refer to milin or milen, ar ster (the river) vilen), or, more likely, the yellow river (melen, ar ster velen), in connection with the colour of the muddy bottoms of the river.