buffer
The definition for buffer is "Protective barrier." Used in a sentence: The dense trees acted as a buffer against the heavy rain.
cunning
The definition for cunning is "Showing clever insight." Used in a sentence: The general devised a cunning strategy to outfox the enemy.
discern
The definition for discern is "To recognize as separate as distinct." Used in a sentence: The pastry connoisseur was able to discern Swiss from Belgian chocolate.
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.
preclude
The definition for preclude is "To rule out in advance." Used in a sentence: "Having cake now will preclude dessert later," said Amber's mother.