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.
beneficial
The definition for beneficial is "Helpful." Used in a sentence: there is no doubt that eating vegetables is beneficial to one's health.
gravity
The definition for gravity is "Importance, significance." Used in a sentence: Understanding the gravity of his error, Ken offered his humblest apology.
refurbish
The definition for refurbish is "To brighten or freshen." Used in a sentence: Leeanne cleaned and mended all weekend to refurbish the shabby apartment.
scapegoat
The definition for scapegoat is "Someone who bears the blame for others." Used in a sentence: Audrey used her innocent baby brother as a scapegoat for the missing cookies.