Linguist Arika Okrent of Mental Floss explains via wonderful whiteboard illustration by Sean O’Neill, how the words “terrific” and “terrible came to mean two very different things despite coming from the same source – terror.
Terrible and terrific. They both come from the same place…terror. And they both started out with the meaning terror-inducing. But terrific took a strange turn and ended up meaning really great. While terrible stayed on the dark side, meaning, well, terrible. This happened through a gradual reshaping of the connotations of terrific. 200 years ago you could talk about a terrific or terrible nightmare or terrific or terrible pain and mean that these things were truly terrifying. But the words might also be used with a bit of dramatic exaggeration. A terrific clamor might not be truly terrifying, just really intense, a whole lot of clamor. A terrible child might not cause people to quake with fear, but just be very bad-mannered. Both terrible and terrific got reduced, but while terrible shifted from terrifying to very bad, terrific shifted to a general sense of more intense than usual.