civility
The definition for civility is "Politeness." Used in a sentence: The usually unruly Thomas acted with great civility when his favorite uncle visited.
elate
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.
ethical
The definition for ethical is "Conforming to accepted standards." Used in a sentence: Mary did the ethical thing and turned in the diamond necklace she found.
flaw
The definition for flaw is "An imperfection." Used in a sentence: The otherwise perfect diamond had a tiny flaw that reduced its value.
opportune
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.