A punchline is the part of a story, comedy sketch, or joke that delivers the funny part that has the punch. There are punchline quotes that talk about the impact that these few words or sentences can have. If you tell a joke but you fail to deliver the punchline properly then it may not seem funny to your listeners and they may not get it. The punchline is the part that makes the whole thing funny, and without it the most humorous story may be dry as toast. The word punchline can also be referred to the most important part of a story, and in this use it may or may not be funny. Any punchline has to have oomph in order to be effective, if this is missing then you will fall flat instead of getting the desired results.