GEDAN NAGASHI UKE
The defensive technique accompanying for the lower range deflects the attacks arriving at the gedan level in the opposite direction of the gedan barai.
No particular position is preferred for the Gedan nagashi uke. Depending on the situation, the defense is mainly executed in Zenkutsu dachi, Kōkutsu dachi or even Fudō dachi. Gedan nagashi uke does not appear in the Kata. However, it is a popular defensive technique in combat because it can be used instinctively. It is often used to ward off Mae geri.
You can find the matching book here:
The Essence of Karate