The word "condentation" doesn't exist, but I suppose you mean condensation.
It means the process of increasing the density of an object - for example, by removing water from it. Condensation also happens when you heat water up until it starts evaporating, and then the vapor transforms back into drops of water on the lid. The word is frequently used to signify the chemical process by which a gas changes into a liquid state. You can also "condense" something in a way to make it more concise.
