The definition for illuminate is "To make clear." Used in a sentence: Her excellent lecture illuminated the complicated subject of nuclear physics. The definition for disconcert is "to throw into confusion.", the definition for ethical is "Conforming to accepted standards.", and the definition for incisive is "Impressively direct and decisive."

The definition for exasperation is "The state of being irritated." Used in a sentence: The longer Jorge waited in line at the ticket counter, the more his exasperation grew. The definition for interminable is "never ending, or seemingly endless.", the definition for straddle is "To favor opposing sides.", and the definition for combustion is "Act of burning."

The definition for fragile is "Delicate." Used in a sentence: Jade placed the fragile vase out of reach of her rambunctious boys. The definition for compulsion is "an irresistible impulse.", the definition for punctual is "On time.", and the definition for servile is "Fearfully submissive."

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. The definition for genial is "sympathetic, friendly.", the definition for prominence is "Importance.", and the definition for diffident is "Lacking self–confidence."

The definition for avian is "Relating to birds." Used in a sentence: The old man affectionately referred to pigeons as his "avian friends." The definition for preclude is "to rule out in advance.", the definition for turmoil is "Extreme confusion, agitation.", and the definition for proximity is "Closeness."