Semantics probably won't help you find out the meaning of a word you don't understand, though it does have a lot to say about the patterns of meaningfulness that you find in words. It certainly can't help you understand the meaning of one of Shakespeare's sonnets, since poetic meaning is so different from literal meaning. But as we learn more about semantics, we are finding out a lot about how the world's languages match forms to meanings. And in doing that, we are learning a lot about ourselves and how we think, as well as acquiring knowledge that is useful in many different fields and applications.