Period 3 Word of the Week - enigma

This week period 3 chose enigma as our word of the week.  An enigma is:

1. a puzzling or inexplicable occurrence or situation;
2. a person of puzzling or contradictory character;
3. a saying, question, or picture containing a hidden meaning; a riddle.

Our sentence that correctly uses the word enigma is:

All the windows in the house suddenly opened; it was a frightening enigma!