This is an unusual word, and you will probably have to add it to your spell-checker. The only reason I know it is that it was recently sent to me by a friend. Paraprosdokians are sentences in which the latter part or a following sentence has an unexpected, humorous twist.
Winston Churchill loved them. So do I.
It is easier understood by example. One is: If I agreed with you, we’d both be wrong. A Google search of paraprosdokians will uncover many more.