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.
drub
The definition for drub is "To defeat decisively." Used in a sentence: The powerful young boxer drubbed the longtime champion.
garish
The definition for garish is "Offensively bright." Used in a sentence: The garish wallpaper offended Jerome, who preferred subtle colors.
incumbent
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.
oblivious
The definition for oblivious is "Lacking awareness." Used in a sentence: Love–struck Charlie was oblivious to everyone but the object of his affection.