The crossword solutions for the term SOAK FLAX are RET. Soaking flax is a process used to soften the fibers of the flax plant, which is then used to make linen fabric. The soaking process involves submerging the flax in water for an extended period of time, usually overnight. This process is known as retting and is necessary to make the fibers of the flax plant more pliable and easier to work with.