What is the name of the circles in water?

Radial gravity waves. When you throw a pebble into a pond, a group of waves radiates out from the point of impact. Waves radiating out from a central point can be rightly called radial waves. read more

If you mean those that result from throwing a rock in the water: There is no specific word for the shock waves the emanate out from where an object penetrated the water. There are many words that partially describe them. read more

Dante designates all of lower hell--circles 6 through 9, where more serious sins are punished--as the walled city of Dis (Inf. 8.68), one of the names for the king of the classical underworld (Pluto) and--by extension--the underworld in general. read more