The definition for placebo is "An inactive substance used in medical testing." Used in a sentence: Tom, who had taken the placebo, found that his allergy symptoms did not go away. The definition for antidote is "something that relieves or counteracts.", the definition for gravity is "Importance, significance.", and the definition for iridescent is "Having a lustrous or attractivve quality."

The definition for oblivious is "Lacking awareness." Used in a sentence: Love–struck Charlie was oblivious to everyone but the object of his affection. The definition for extol is "to praise highly.", the definition for salvage is "To save from ruin.", and the definition for dubious is "Questionable."

The definition for trove is "Valuable collection." Used in a sentence: Walter's trove of vintage baseball cards was worth thousands of dollars. The definition for apathetic is "showing little or no emotion.", the definition for commemorate is "To mark by a ceremony.", and the definition for polarize is "To break up into opposing groups."

The definition for rancorous is "Marked by deep ill–will." Used in a sentence: The rancorous competition between the two chess clubs actually ended in a brawl. The definition for epistolary is "contained or carried on in letters.", the definition for belated is "Past the normal or proper time.", and the definition for naive is "Lacking worldy wisdom."

The definition for parity is "Equality." Used in a sentence: Hilda, to avoid squabbles, aimed for parity in the slices of birthday cake. The definition for moderate is "tending toward the average.", the definition for frugal is "Thrifty, cheap.", and the definition for heinous is "Shockingly evil."