The word "young" is an adjective that means being in the early stages of growth or immature. The best choice here is "juvenile" since it shares the same definition as "young"—immature. Considering the other choices, "ill" is an adjective that means physically sick, "excessive" means being in too large of a quantity or more than is needed, "idyllic" means ideally charming or romantic, and "belligerent" means eager to fight.

“Transitory” means impermanent or not lasting, so "impermanent" is the correct answer. As for the other answer choices, “nomadic” means living a lifestyle in which one wanders and does not live in one place; "expedited" means hastened; "foreign" means originating in a country different from one's own; and “explosive” means volatile or likely to explode like a bomb.

“Wizened” means very old and wrinkled with age, so "aged" is the correct answer. As for the other answer choices, “sage” means wise when used as an adjective; “serene” means quiet and peaceful; “lofty” means high and proud; and “haughty” means arrogant.

“Wanton” means random, but it also can mean cruel and malicious. Most commonly it is used to mean random and destructive, so "random" is the correct answer. As for the other answer choices, “mercurial” means changing emotions, decisions, or plans on a whim; “predictable” means easily anticipated; “dormant” means inactive or asleep; and “overzealous” means too passionate or overly enthusiastic.

"Extant" and "contemporary" both mean existing in the present. "Extinct" means dead or obsolete. "Diffident" means hesitant or unconfident. "Ephemeral" means momentary or passing. "Equivocal" means doubtful or uncertain. 

Do not confuse the word “imminent” with “immanent,” which means “being within something” or “innate.” The word “imminent” means “something that will occur very soon.” For instance, it would be used in a sentence like, “While many believed that another world war was unlikely to happen in the next several months, John sincerely thought such a danger was imminent.”

Antiquated, while it sounds like antique, refers to something being old or outdated, not beautiful and detailed. So in this set, the best answer would be outmoded, which means worn out or old.

"Nascent" is an adjective that means "just coming into existence and beginning to display signs of future potential," and is especially used to refer to a process or organization. So, we need to pick out an answer choice that means something lie "just coming into existence." "Experienced," then, cannot be the correct answer, because "experienced" means "having knowledge or skill in a particular field, especially a profession or job, gained over a period of time," making "experienced" an antonym of "nascent," not a synonym. "Incipient," however, is an adjective that means either "in an initial stage; beginning to happen or develop," or when used of a person, "developing into a specified type or role." Because "incipient" is the answer choice closest in meaning to "nascent," "incipient" is the correct answer.

There may be many meanings that come to mind when thinking of the word “eternal,” but only the idea of “timelessness” is most appropriate. It literally means “having no beginning or end in time.” This is the only acceptable answer among those provided.

When people become weak as they age, they reach a point at which they are often called “senile.” This often implies not merely physical weakness but more often imply mental weakness and disability. While the options “insane” and “crazed” might tempt you, the best option is the simple “feeble.” The other two options are more than mental feebleness but could indicate a pathology that is unrelated to aging. In the American system of government, “senators” are given that name because they are supposed to be the “old men,” wiser than more youthful representatives.