adversary
The definition for adversary is "One who opposes or resists." Used in a sentence: Franklin hoped to defeat his adversary in the afternoon's tennis match.
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.
extant
The definition for extant is "Currently existing." Used in a sentence: Some consider Clint Eastwood the greatest extant American director.
liability
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.
turmoil
The definition for turmoil is "Extreme confusion, agitation." Used in a sentence: The windstorm caused such turmoil in the lake that the sailboat capsized.