Resultant is a rather formal way to say that something happened or exists because of something else. If a storm hits a town, the resultant damage is the damage the storm left behind. It almost always sits in front of a noun: resultant delays, resultant costs, resultant chaos. You will mostly see it in reports, news, and science, not in easy chat. A speaker at a meeting might say “the resultant delays”; a young person would more likely say “so then everything was late.” Though actually, the word has a second, more technical life: in physics, the resultant is the one force you get when several forces push at once. Same idea underneath — many things act, and this is what you are left with — but that noun use stays in the classroom and the lab. In ordinary English, do not stretch resultant to mean “the result” on its own. People just say “the result” for that.