An atrocity is something horrific.

Flattery means to compliment someone.

"Trek" is a word meaning "a long arduous journey, especially one made on foot," so we need to pick out another word that means something like "journey." Since "expedition" means "a journey or voyage undertaken by a group of people with a particular purpose, especially that of exploration, scientific research, or war," "expedition" is the answer choice closest in meaning to "trek," so "expedition" is the correct answer.

"Intuition" is a noun that means "the ability to understand something immediately, without the need for conscious reasoning," so we need to pick out another noun that means something like "unconscious understanding." While "intention" may seem like a good answer choice because it sounds like "intuition," "intention" means "a thing intended; an aim or plan." Since "intuition" does not mean the same thing as "intention," it cannot be the correct answer. "Hunch," however, is a noun that means "a feeling or guess based on intuition rather than known facts," it is the answer choice closest in meaning to "intuition" and thus the correct answer.

A "flux" is a flow or a condition of constant change.

A "hiatus" is a break.

"Nicety" is a noun that can mean "a fine detail or distinction, especially one regarded as intricate and fussy," "accuracy and precision," or "a minor aspect of polite social behavior; a detail of etiquette." So, we need to pick out an answer choice that means something like "a fine detail," "accuracy," or "a detail of etiquette." "Attribute," a word that when used as a noun means "a quality or feature regarded as a characteristic or inherent part of someone or something," might look like the correct answer because both "nicety" and "attribute" can refer to characteristics, but "subtlety" is actually the better answer, because "subtlety" can mean "a subtle distinction, feature, or argument," and better captures the connotation of fineness, intricateness, or fussiness that is part of the word "nicety." So, "subtlety" is the correct answer.

"Delusion" is a noun that means "a belief that is firmly maintained despite being contradicted by accepted as reality, typically a symptom of mental disorder," or "the action of deluding someone or the state of being deluded." So, we need to pick out a noun that means something like "misinterpretation." "Actuality," then, cannot be the correct answer, because "actuality" means "actual existence, typically as contrasted with what was intended, expected, or believed," making it an antonym, not a synonym, of "delusion." "Fallacy," however, is a noun that can mean "a mistaken belief, especially one based on unsound argument," and because "fallacy" is the answer choice closest in meaning to "delusion," "fallacy" is the correct answer.

“Zeal” is a noun that means “great energy or enthusiasm in pursuit of a cause or an objective,” so we need to pick out an answer choice that means something like “great energy or enthusiasm.” That means that “ennui” cannot be the correct answer, because “ennui” is a noun that means “a feeling of listlessness and dissatisfaction arising from a lack of occupation or excitement,” making it an antonym, not a synonym, of “zeal.” “Fervor,” however, is a noun that means “intense and passionate feeling,” and because “fervor” is the answer choice closest in meaning to “zeal,” “fervor” is the correct answer.

“Reprieve” is a word that can be used as a verb or a noun, but because all of the answer choices are nouns, we need to consider “reprieve” as a noun. When used as a noun, “reprieve” can mean “an official order that delays the punishment of a prisoner who is sentenced to death,” “a delay that keeps something bad from happening,” or “a period of relief from pain or trouble.” So, we need to pick out an answer choice that means something like “an official order that delays a prisoner’s execution,” “a delay that keeps something bad from happening,” or “a period of relief.” That means that “agony” cannot be the correct answer, because “agony” means “extreme physical or mental suffering” or “the final stages of a difficult or painful death,” making it an antonym, not a synonym, of “reprieve.” “Respite,” however, is a noun that means “a short period of rest or relief from something difficult or unpleasant,” and because “respite” is the answer choice closest in meaning to “reprieve,” “respite” is the correct answer.