negate
The definition for negate is "To make invalid." Used in a sentence: Paula negated Tiffany's argument by proving that her main premise was false.
pantomime
The definition for pantomime is "Telling a story through gestures." Used in a sentence: The jealous actress called her understudy's performance a ridiculous pantomime.
repel
The definition for repel is "To resist, reject." Used in a sentence: The soldiers made a massive charge to repel the invaders.
sociable
The definition for sociable is "Inclined to seek companionship." Used in a sentence: The sociable Glenda was delighted to receive the party invitation.
stern
The definition for stern is "Harsh, severe." Used in a sentence: The stern principal canceled the prom after the seniors played a silly prank.