gargantuan
The definition for gargantuan is "Gigantic." Used in a sentence: The gargantuan monster towered over the ten–story bulding.
impenitent
The definition for impenitent is "Lacking remorse." Used in a sentence: The impenitent criminal received a harsh penalty, but his remorseful accomplice was released.
incumbent
The definition for incumbent is "Necessary as a duty or responsibility." Used in a sentence: It was incumbent on Jack to attend his father's retirement party.
plaudits
The definition for plaudits is "Enthusiastic approval." Used in a sentence: Allison's painting met with plaudits from the critics, who had dismissed her earlier work.
stealth
The definition for stealth is "The act of moving secretly or unnoticed." Used in a sentence: The burglar took the ring by stealth, slipping it from the sleeping woman's finger.