archaic
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.
colossal
The definition for colossal is "Immense, enormous." Used in a sentence: After pushing with all his might, Frank realized he could never move the colossal boulder.
precept
The definition for precept is "A general rule of action." Used in a sentence: All the students know Mrs. Brown's strict precept; no talking in class.
serenity
The definition for serenity is "Calmness." Used in a sentence: The serenity of the glassy sea soothed the sailors after the big storm.
trove
The definition for trove is "Valuable collection." Used in a sentence: Walter's trove of vintage baseball cards was worth thousands of dollars.