Meaning: Rectitude refers to behavior that is correct, upright and honorable.
Rectitude is being morally correct.
Example: He encouraged the graduates to go on to live lives of unimpeachable rectitude and integrity.
Synonyms: Decency, Honesty, Morality, Probity
Antonyms: Dishonesty, Immorality, Corruption, Evil

Meaning: Candor usually means the quality of being open, honest, and sincere.
Example: As a token of candor, reveal to me your chief passion.
Synonyms: Fairness, Frankness, Honesty, Sincerity
Antonyms: Deceit, Unfairness, Lying, Deception

Meaning: Someone who is imperious gives orders in a way that shows they feel superior or more important than other people.
The meaning of imperious is someone or something that is domineering and demanding, without any justification or right.
Example: Although she is talented yet imperious.
Synonyms: Arrogant, Bossy, Overbearing, Domineering, Dictatorial, Haughty
Antonyms: Humble, Meek, Fawning, Obedient, Weak

Meaning: The meaning of erstwhile is something from an earlier time.
It denotes in the past; a former time; formerly.
Example: My erstwhile friend ignored me when I ran into her at the mall.
Synonyms: Bygone, Ex, Old, Past, Former, Expired
Antonyms: Ongoing, Current, Present, Extant

Meaning: Penitence is the state of having regret for doing something wrong.
Example: She cut off her hair as a token of penitence for her mistakes.
Synonyms: Penance, Repentance, Contrition, Compunction, Remorse
Antonyms: Approval, Comfort, Contentedness, Satisfaction