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 comparable is "Similar, equivalent." Used in a sentence: Helen will only accept something of comparable value for her ticket to the concert.

The definition for mediate is "To come between parties in order to reconcile." Used in a sentence: The diplomatic Henry was able to mediate between the quarreling sisters.

The definition for placebo is "An inactive substance used in medical testing." Used in a sentence: Tom, who had taken the placebo, found that his allergy symptoms did not go away.

The definition for prominence is "Importance." Used in a sentence: The singer's prominence ensured that the concert would sell out.