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.

The definition for epistolary is "Contained or carried on in letters." Used in a sentence: The shoebox filled with letters was the ony remains of Ming's epistolary friendship with Emile.

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.

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 rancorous is "Marked by deep ill–will." Used in a sentence: The rancorous competition between the two chess clubs actually ended in a brawl.