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.
apathetic
The definition for apathetic is "Showing little or no emotion." Used in a sentence: Carmine was concerned about his usually cheerful brother's apathetic attitude.
condone
The definition for condone is "To treat as acceptable." Used in a sentence: Crystal condoned her friend's late arrival because she found it hard to be on time herself.
flaw
The definition for flaw is "An imperfection." Used in a sentence: The otherwise perfect diamond had a tiny flaw that reduced its value.
redouble
The definition for redouble is "To make twice as great." Used in a sentence: As the sun began to set, Brittany redoubled her effort to find the necklace she had dropped in the field.