The definition for iridescent is "Having a lustrous or attractivve quality." Used in a sentence: The movie star's iridescent presence charmed even the hardened reporter. The definition for corroborate is "to support with evidence.", the definition for corrosive is "Bitingly sarcastic.", and the definition for mandate is "An official order or commission to do something."

The definition for servile is "Fearfully submissive." Used in a sentence: Felicia's servile attitude annoyed her boss, who preferred an assistant with more backbone. The definition for comprehensible is "understandable.", the definition for exasperation is "The state of being irritated.", and the definition for retroactive is "effective as of a prior time or condition."

The definition for augment is "To make greater." Used in a sentence: Wanda read the dictionary every night to augment her vocabulary. The definition for turpitude is "essential baseness, depravity.", the definition for fraud is "Trick.", and the definition for colossal is "Immense, enormous."

The definition for civility is "Politeness." Used in a sentence: The usually unruly Thomas acted with great civility when his favorite uncle visited. The definition for apathetic is "showing little or no emotion.", the definition for placebo is "An inactive substance used in medical testing.", and the definition for precept is "A general rule of action."

The definition for prune is "To reduce by removing excess." Used in a sentence: The candidate pruned his speech so he would not exceed the time limit. The definition for straddle is "to favor opposing sides.", the definition for untenable is "Not able to be defended.", and the definition for unscrupulous is "Lacking principles."