appalling
The definition for appalling is "Inspiring dismay or disgust." Used in a sentence: Hector found his roommate's habit of leaving his dirty socks on the floor appalling.
comprehensible
The definition for comprehensible is "Understandable." Used in a sentence: Shannon spoke slowly so her directions would be comprehensible to her foreign visitor.
meticulous
The definition for meticulous is "Extrememly careful regarding details." Used in a sentence: The meticulous detective found every shred of evidence at the crime scene.
placebo
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.
retroactive
The definition for retroactive is "effective as of a prior time or condition." Used in a sentence: The retroactive law made even past infractions punishable.