Abject usually describes things that are extremely bad or severe. It can also describe something that feels or shows shame, or someone lacking courage or strength.

// Happily, their attempts to derail the project ended in abject failure.

// The defendants were contrite, offering abject apologies for their roles in the scandal that cost so many their life savings.

// The author chose to cast all but the hero of the book as abject cowards.

Contrite is a formal adjective used to describe someone who feels regret for their bad behavior, or something, such as an apology, that shows such regret.

// Although the mayor appeared contrite about the most recent scandal plaguing city hall, many constituents remained unpersuaded.

Impunity, usually used in the phrase "with impunity," refers to exemption or freedom from punishment, harm, or loss.

// They mistakenly believe that they can break the camp's rules with impunity.

To rescind something, such as a law, contract, agreement, etc., is to end it officially. Rescind can also mean “to take back; to cancel.”

// Given the appeal court’s recent decision, it is likely that the law will be rescinded.

// The company later rescinded its offer.

Boffo is an informal word that describes things that are extremely good or successful.

// The most recent film in the long-running franchise has done boffo business at the box office, a testament to the series’ enduring popularity.

A simulacrum is a superficial likeness of something, usually as an imitation, copy, or representation. The plural of simulacrum is either simulacrums or simulacra.

// The surprise still succeeded, thanks to the simulacrum of confusion expressed by two guests when they were spotted before the big moment.

To procrastinate is to be slow or late about doing something that should be done, or about doing or attending to things in general.

// Tickets to the event are selling swiftly, so don't procrastinate—buy yours today.

// Not one to procrastinate, Harry set to work on the project immediately.

Antic refers to an attention-drawing, often wildly playful or funny act or action. It is usually used in its plural form, and is often used disapprovingly.

// It wasn't clear which students were ultimately responsible for the antics that unfolded in the cafeteria that day.