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 exalt is "To elevate by praise." Used in a sentence: The fireman was publicly exalted for his heroism.

The definition for finite is "Having definite limits." Used in a sentence: The exasperated mother had finite patience for her toddler's tantrums.

The definition for liability is "A person or thing whose presence or behavior is likely to cause embarrassment or put one at a disadvantage." Used in a sentence: Kevin's growing fatigue was a liability as he attempted to climb the steep hill.

The definition for retroactive is "effective as of a prior time or condition." Used in a sentence: The retroactive law made even past infractions punishable.