ravine, valley, (kokuji)
逧 centers on a narrow, steep-sided valley or ravine. It is a kokuji created in Japan to express this specific landscape feature.
逧 is a Japanese kokuji, combining the movement radical ⻌ with 谷 (valley) to represent a ravine or valley path. It was likely created to describe a specific topographical feature.
The movement radical ⻌ suggests a path, and 谷 is a valley. Picture a winding path leading deep into a narrow ravine: 逧 is that ravine.
For さこ, imagine a small echo (さ, from ささやく whisper) bouncing off the steep walls of a narrow valley (こ, like 子, a small child, suggesting a small, enclosed space). Together, さこ is the sound of a whisper echoing in a ravine.