fraud
The definition for fraud is "Trick." Used in a sentence: The con man's fraud involved selling swampland to gullible investors.
gruff
The definition for gruff is "Rough or stern in manner or speech." Used in a sentence: Heidi's grandfather was gruff, barking stern orders and hardly smiling.
polarize
The definition for polarize is "To break up into opposing groups." Used in a sentence: Thelma tended to polarize discussions rather than to encourage compromise.
proximity
The definition for proximity is "Closeness." Used in a sentence: The proximity of Tia's house to school meant that she could walk there in five minutes.
retroactive
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.