A zygote is a fertilized egg cell produced by the fusion of a female gamete and a male gamete
Implantation is the process by which a blastocyst which is advancing through the uterus as a developing embryo, makes contact with the uterine wall and remains attached to it until birth.
Through a series of internal changes, the uterine lining (endometrium) is ready for the growing blastocyst to bind to it.
Final answer: Fixing of developing zygote on the uterine wall is implantation.