Temerity is the possession of boldness and confidence – quite the opposite of Timorous. It sounds like a positive attribute but can so easily made negative with a statement like:

“You have the temerity to come round here and ask me a question like that?!

Learn a new word every day.
Repeat it and remind yourself what it means at least three times in a day.
Try to use the word in conversation or writing today.
Get a dictionary and look words up.