The definition for archaic is "Characteristic of an earlier time." Used in a sentence: In the world of high fashion, two–year–old shoes are considered positively archaic.

The definition for corrosive is "Bitingly sarcastic." Used in a sentence: The cruel Estella's corrosive comments made Pip cry.

The definition for extant is "Currently existing." Used in a sentence: Some consider Clint Eastwood the greatest extant American director.

The definition for onset is "Beginning." Used in a sentence: Crocuses bloom at the onset of spring, sometimes even before the snow melts.

The definition for untenable is "Not able to be defended." Used in a sentence: Rashid made the untenable statement that George Washington was the second president of the United States.