Definition of "Impregnation" :

noun: creation by the physical union of male and female gametes; of sperm and ova in an animal or pollen and ovule in a plant

noun: the process of totally saturating something with a substance

"The impregnation of wood with preservative."

noun: material with which something is impregnated

"The impregnation, whatever it was, had turned the rock blue."