If you discover late Sunday night that the dog really did eat your homework, you might cry out in dismay. Dismay describes an emotional state of alarm, fear, or serious disappointment.
The first part of dismay comes from the Latin prefix dis-, which comes in handy when you want to put a negative spin on words (dishonest, discount, disenchant, etc.). The last bit of dismay most likely comes from the Germanic word magan, meaning "to be able to." You can employ the word dismay to describe how you feel in a variety of negative situations that you doubt you are able to handle.