The word "torrent" evokes images of gushing flood waters, raging currents of water, sweeping everything away, of heavy showers of rain... so I was surprised to learn that it is etymologically derived from a word meaning thirsty, even dry or desiccated. It is a loanword from French: torrent, which originates from Latin torrens -torrentem "rushing stream". As the suffix indicates, it is the ppa (participle present active) of a verb, namely the Latin torrere "to parch".
So, what could be the connection between a rushing stream and something which is dried out, thirsting for some water?
Supposedly, the contrasting meanings are linked by the image of a mountain creek or river which may be a raging current in spring, but dries out in summer.
By the way, the Proto-Indo-European word *ters- simply means "thirsty" or "dry", with no implication of waters, floods, and creeks yet.
In the Vedic (old Indian) language, for example, we have the adjective trshāna meaning "thirsty". The German verb ver-dorren means "dry up", "wither", while the corresponding causative verb dörren means "to parch". There is also the archaic word darren, which denotes the traditional procedure of parching cereals in the oven.