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.
manifest
The definition for manifest is "Obvious." Used in a sentence: James finally made his affection manifest when he handed Jessica a red rose.
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.
perception
The definition for perception is "Capacity for seeing or understanding." Used in a sentence: His incredible perception made him the best detective on the force.
untenable
The definition for untenable is "Not able to be defended." Used in a sentence: Rashid made the untenable statement that George Washington was the second president of the United States.