gainsay

You might have trouble figuring out the meaning of gainsay if you’re thinking of our modern word gain plus say. It should help to know that the gain part comes to us from the Old English word gēan-, meaning “against” or “in opposition to.” In Middle English, gēan- was joined to seyen (“to say”) to form gein-seyen, which led to the modern word gainsay. So when you see gainsay, think “to say against”—that is, “to deny” or “to contradict.”