Yes, there are a couple of different meanings. One of them you would want to be quite careful of using. If you tell someone "Drop dead!" It means that you hate them and though you stop short of murdering them, you wouldn't mind to see them die right there in front of you. This is a really hateful thing to say-- so be careful. Then the other use is as an adjective phrase. I don't know about other English-speaking countries, but in America you can say "She is drop-dead gorgeous!", which means "She is VERY gorgeous." It is an intensifier, but I don't think I have heard it in any other sense than appreciating the beauty of something-- usually a woman, but not always.