Sentence:  The greater the depth of the water , the greater is the speed of the wave ; Lagrange 's law says that its velocity is equal to the square root of the product of the depth times the acceleration due to <WSD>gravity</WSD> . 
Meaning of the word marked with <WSD> tags:  (physics) the force of attraction between all masses in the universe; especially the attraction of the earth's mass for bodies near its surface