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.

The definition for aerate is "To supply with air." Used in a sentence: Every spring, Soloman used his tiller to aerate the compact soil.

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 inviolable is "Secure from assault of trespass." Used in a sentence: Situated on a mountain, with sixteen–foot walls, the castle was inviolable.

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.