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.
civility
The definition for civility is "Politeness." Used in a sentence: The usually unruly Thomas acted with great civility when his favorite uncle visited.
facade
The definition for facade is "false or superficial appearance." Used in a sentence: Emily's smile is just a facade masking her broken heart.
melee
The definition for melee is "A tumultuous fight among several people." Used in a sentence: After the game, a melee broke out between fans of the opposing teams.
pretense
The definition for pretense is "False intention or purpose." Used in a sentence: The jewel thief entered the mansion under the pretense of fixing a leaky faucet.