Spermatize is a term used to describe the process of fertilization in which the sperm cell penetrates the ovum. However, if you are looking to replace the word "Spermatize" in your writing, there are several synonyms that you can choose from. These synonyms include impregnate, inseminate, fertilize, and fructify. Each of these words essentially means the same thing as "Spermatize" and can be used interchangeably in most cases. It's important to choose the right synonym depending on the context of your sentence to convey your message accurately. Regardless, all of these synonyms describe the act of fertilization and the creation of new life.