चतुर्थी = चतुर् + थक् / थ + ङीष् / ई
float again by pulling above water, handling platform + outside top
तुर्थी = knot float up superior platform
meaning explained - knot floaters
चतुर्थी = च त उ ऋ थ इ
knot verb(float+superior) object(platform)
meaning explained: knot with plat form to improve float