The definition for diffident is "Lacking self–confidence." Used in a sentence: The diffident student never raised her hand in class, even when she knew the answer.

The definition for drub is "To defeat decisively." Used in a sentence: The powerful young boxer drubbed the longtime champion.

The definition for elate is "To fill with joy." Used in a sentence: It elated Margaret to be awarded first place in the science fair.

The definition for facade is "false or superficial appearance." Used in a sentence: Emily's smile is just a facade masking her broken heart.

The definition for opportune is "Suitable or convenient." Used in a sentence: Quan stepped onto the platform at the most opportune time, just as the train pulled in.