The definition for incumbent is "Necessary as a duty or responsibility." Used in a sentence: It was incumbent on Jack to attend his father's retirement party. The definition for catastrophic is "relating to extreme misfortune.", the definition for commemorate is "To mark by a ceremony.", and the definition for methodical is "Performed in an orderly manner."

The definition for euphoria is "Feeling of great happiness." Used in a sentence: Cassandra was overcome with euphoria when she met her long–lost sister. The definition for pantomime is "telling a story through gestures.", the definition for duplicity is "Deceptive thought, speech, or action.", and the definition for insolence is "Boldness or rudeness."

The definition for diffident is "Lacking self–confidence." Used in a sentence: The diffident student never raised her hand in class, even when she knew the answer. The definition for repel is "to resist, reject.", the definition for intricate is "Having complex and interrelated parts.", and the definition for insinuate is "To suggest indirectly."

The definition for derivative is "Lacking originality." Used in a sentence: Critics panned the movie as a derivative version of last year's Best Picture. The definition for raucous is "noisy, rowdy.", the definition for celebrated is "Widely known, respected.", and the definition for comprehensible is "Understandable."

The definition for interminable is "Never ending, or seemingly endless." Used in a sentence: The impatient Zoe found the longwinded lecture interminable. The definition for proximity is "closeness.", the definition for aesthete is "Person having or affecting sensitivity to beauty.", and the definition for condone is "To treat as acceptable."