The definition for accessible is "Easy to reach or to approach." Used in a sentence: The introduction to the complex novel was, thankfully, written in clear accessible language.

The definition for impenitent is "Lacking remorse." Used in a sentence: The impenitent criminal received a harsh penalty, but his remorseful accomplice was released.

The definition for methodical is "Performed in an orderly manner." Used in a sentence: Oscar's methodical approach exasperated his free–spirited friend Ben.

The definition for oblivious is "Lacking awareness." Used in a sentence: Love–struck Charlie was oblivious to everyone but the object of his affection.

The definition for placebo is "An inactive substance used in medical testing." Used in a sentence: Tom, who had taken the placebo, found that his allergy symptoms did not go away.