The definition for compulsion is "An irresistible impulse." Used in a sentence: Tamar, a shoe fanatic, could not resist the compulsion to buy the shiny red boots.

The definition for egotist is "Self–important person." Used in a sentence: Darren dreaded carpooling with the egotist Shelly, who talked about herself nonstop.

The definition for ploy is "A contrived plan." Used in a sentence: Sarah thought George's ploy of borrowing her notes was a cowardly way to ask her out.

The definition for prudent is "Marked by wisdom, shrewd." Used in a sentence: Manny was happy she followed Greg's prudent advice to study, as the test was difficult.

The definition for serenity is "Calmness." Used in a sentence: The serenity of the glassy sea soothed the sailors after the big storm.