Spermicidal describes something that kills sperm — the tiny cells from a man's body that can make a woman pregnant. It is the adjective for spermicide. You will almost always meet it in front of a noun, in phrases like spermicidal cream, spermicidal gel, spermicidal foam, or spermicidal jelly, and on the box of some condoms: "spermicidal lubricant". So it is not really a word people say about a person or a feeling; it is a word printed on a product, used by doctors, pharmacists and health teachers. The tone is clinical and matter-of-fact — a nurse says it without embarrassment, and that is the register you should copy if you ever need it. Note that -cidal words in English are built the same way and all mean "killing that thing": you can also read of a chemical being described as spermicidal in a science paper about animals or plants, where nobody is talking about birth control at all. One more thing worth knowing: teachers of health often add that spermicidal products alone are not very reliable, so the word appears a lot in sentences about using it *with* something else.

殺精的、含殺精劑的（如「殺精避孕膏」「殺精凝膠」）