Synonyms

Peremptory means commanding or dictatorial in manner, admitting no refusal or contradiction. Authoritative is the closest match as it also conveys a commanding, self-assured tone. The other options (polite, meek, accessible, conditional) are opposite or unrelated to peremptory's dominant nature.

 To palliate something means to soothe something and mitigate is the correct synonym.

 'Ashen' is the correct synonym for 'pallid' as they both mean pale.

Chatter is synonymous to palaver.

A pandemic refers to a disease outbreak that spreads across countries or continents, affecting a large population. "Widespread disease" correctly captures this meaning. The other options (contained, controlled) are opposites, while arrogant and assertive are personality traits unrelated to the term.

Nonviolent is the correct synonym for pacifist here as they both refer to someone who prefers peace or is opposed to the use of violence.

Hypocrisy means duplicity or falseness.

Legitimate means 'valid' or 'justifiable'.

Feeble means 'weak' or 'frail'.

'Tyrannical' means someone who is exercises power in a cruel way and 'oppressive' means the same.  

To 'interdict' means to prohibit or forbid something officially. 'Prohibit' is the direct synonym among the choices.

 Calumny is back-biting and making false and derogatory statements. So, slander meaning the same as calumny is the correct answer.

An 'inveterate' habit or feeling is long-established and unlikely to change. 'Chronic' is a synonym used to describe persisting or long-lasting conditions.

'Disparate' means essentially different in kind or entirely unlike. 'Dissimilar' is the closest synonym among the options.